530 research outputs found
Cellular immune reactions of the sunn pest, Eurygaster integriceps, to the entomopathogenic fungus, Beauveriabassiana and its secondary metabolites
In this study, five morphological types of circulating hemocytes were recognized in thehemolymph of the adult sunn pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae),namely prohemocytes, plasmatocytes, granulocytes, adipohemocytes, and oenocytoids. Theeffects of the secondary metabolites of the entomopathogenic fungus Beauveria bassiana oncellular immune defenses of Eurygaster integriceps were investigated. The results showed thatthe fungal secondary metabolites inhibited phagocytic activity of E. integriceps hemocytes andhampered nodule formation. A reduction of phenoloxidase activity was also observed. The datasuggest that B. bassiana produce secondary metabolites that disable several immune mechanismsallowing the fungus to overcome and then kill its host. This characteristic makes B. bassiana apromising model for biological control of insect pests such as E. integriceps
Amyloid/Melanin distinctive mark in invertebrate immunity
Protostomes and Deuterostomes show the same nexus between melanin production, and amyloid
fibril production, i.e., the presence of melanin is indissolubly linked to amyloid scaffold that, in turn, is
conditioned by the redox status/cytoplasmic pH modification, pro-protein cleavage presence,
adrenocorticotropin hormone (ACTH), melanocyte-stimulating hormone (\u3b1-MSH), and neutral
endopeptidase (NEP) overexpressions. These events represent the crucial component of immune
response in invertebrates, while in vertebrates these series of occurrences could be interpreted as a
modest and very restricted innate immune response. On the whole, it emerges that the mechanisms
involving amyloid fibrils/pigment synthesis in phylogenetically distant metazoan (viz, cnidaria,
molluscs, annelids, insects, ascidians and vertebrates) are evolutionary conserved. Furthermore, our
data show the relationship between immune and neuroendocrine systems in amyloid/melanin
synthesis. Indeed the process is closely associated to ACTH-\u3b1-MSH production, and their role in
stress responses leading to pigment production reflects and confirms again their ancient phylogeny
Functional amyloid formation in LPS activated cells from invertebrates to vertebrates
LPS stimulation provokes serious cellular stress with an increase of cytoplasmic reactive oxygen species (ROS). We have investigated, among the different cellular defenses, amyloidogenesis as common physiological response to attenuate oxidative stress. Optical and electron microscopic observations of the following LPS activated cell lines [insect (larval hemocytes, IPLB-LdFB and Drosophila Schneider\u2019s S2 cells); mouse (NIH3T3 embryonic fibroblasts); Human (Human Umbilical Vein Endothelial Cells (HUVEC), neutrophils, and mesenchymal stem cells] reveal that, all are characterized by irregular profiles, cytoplasmic empty vacuoles or by cisternae containing fibrillar material. The compartmentalized fibrillar material shows staining properties typical of amyloid fibrils. LPS activation leads to ROS generation, resulting in pH acidification. Stimulated cells show pink cytoplasm in May-Gr\ufcnwald Giemsa differential staining, giving a gross indication of a lower intracellular pH. Moreover the activation of amyloidogenesis is also linked with an extensive production of ACTH and \u3b1-MSH in all cultured cell types. We suggest that amyloidogenesis is a common, physiological cellular response to weak ROS, starting when other anti-stress cellular systems failed to restore homeostasis. The morphological evidence and/or functional characterization of synthesized amyloid fibrils could be an early indicator of oxidative stress that may lead to a general inflammatory process
Recent X-ray Observations and the Evolution of Hot Gas in Elliptical Galaxies: Evidence for Circumgalactic Gas
X-ray emitting gaseous halos, such as that in elliptical galaxies like NGC
4472, cannot have been produced solely from gas expelled from galactic stars.
In traditional models for the evolution of hot interstellar gas (cooling flows)
in ellipticals, the galaxies are assumed to have been cleared of gas by
SNII-driven winds at some early time then gas is subsequently replenished by
mass loss from an evolving population of old stars. To test this, we accurately
determine the stellar and dark halo mass of NGC 4472 using hydrostatic
equilibrium, then solve the standard time-dependent cooling flow equations to
recover the observed hot gas temperature and density distributions when evolved
to the present time. This procedure fails: the computed gas density gradient is
too steep, the total gas mass is too low, and the gas temperatures are much too
low. All variants on this basic procedure also fail: increasing the SNIa rate,
using the mass dropout assumption, arbitrarily adjusting uncertain
coefficients, etc. However, agreement is achieved if the galaxy is supplied
with additional, spatially-extended hot gas early in its evolution. This old
``circumgalactic'' gas can be retained to the present time and may be related
to cosmological ``secondary infall''.Comment: 15 pages in two-column AASTEX LaTeX including 1 table and 8 figures;
abstract corrected in replacement; accepted by Astrophysical Journa
Study of the MgB2 grain size role in ex-situ multifilamentary wires with thin filaments
The MgB2 superconductor has already demonstrated its applicative potential,
in particular for DC applications such as MRI magnets, thanks to the low costs
of the raw materials and to its simple production process. However further
efforts have still to be made in order to broaden its employment also towards
the AC applications such as SFCL, motors, transformers. The main issues are
related to the reduction of the AC losses. Some of these can be faced by
obtaining multifilamentary conductors with a large number of very fine
filaments and, in this context, the powders granulometry can play a crucial
role. We have prepared MgB2 starting powders with different granulometries and
by the ex-situ P.I.T method we have realized multifilamentary wires with a
number of filaments up to 361 and an average size of each filament lowered down
to 30 microns. In particular we have studied the relationship between grain and
filament size in terms of transport properties and show that the optimization
of this ratio is possible in order to obtain suitable conductors for AC
industrial applications
When IL-17 inhibitors fail : real-life evidence to switch from secukinumab to adalimumab or ustekinumab
Psoriasis is a chronic, systemic inflammatory disease that in the moderate to severe forms may benefit of biologics, namely TNF and IL-12/23 and IL-17 inhibitors. Loss of response, lack of response or discontinuation due to adverse events represent a concrete therapeutic challenge for dermatologists that have to switch patients to other treatments. Although some evidences already exist toward the switch from IL-12/23 and TNF inhibitors to IL-17 inhibitors, conversely nothing is present toward the switch from IL-17 inhibitors to IL-12/23 and TNF inhibitors. We performed a real-life study enrolling 50 patients randomly switched to adalimuamb, a TNF inhibitor, or ustekinumab, an IL-12/23 inhibitor. Our observational study suggests that switching from IL-17i to TNFi and IL-12/23i is a safe and effective therapeutic strategy
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