126 research outputs found

    Silver fir (Abies alba Mill.) is able to thrive and prosper under meso-Mediterranean conditions

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    The potential ecological envelope of silver fir (Abies alba Mill.) based on its present distribution suggests a high suitability for moist rather than warm and dry environments. This contrasts with paleoecological evidence reporting its former presence at low elevations under meso-Mediterranean conditions. In this study, we evaluated the growth performance of silver fir at low elevation (20–60 m a.s.l.) under meso-Mediterranean climatic conditions in Tuscany (central Italy). We conducted a dendroecological analysis on Abies alba trees along a geomorphological gradient (from depression to upper slope conditions). Climate-growth relationships were assessed by means of correlations, response functions, pointer years, and superposed epoch analysis. Silver fir was found to grow and regenerate well in these stands mixed with evergreen (e.g., Quercus ilex L.) and thermophilous deciduous Mediterranean tree species (e.g., Q. cerris L.). Summer drought was the most growth-influencing factor, with immediate (i.e., current season) negative impacts on tree-ring widths (TRW). No significant impacts were observed in the four years following extreme summer droughts, but the TRW series (which started between the 1930s and 1950s) showed a growth decline since the mid-1990s that is likely drought-related. Our results show that, provided there is a sufficiently large soil water holding capacity, silver fir provenances exist which are able to withstand Mediterranean summer droughts, can naturally and regularly regenerate in these systems, and may even dominate over typical meso-Mediterranean species. As long as annual precipitation is not too low (i.e., >850 mm) and summer drought conditions not too extreme (i.e., less than three months), silver fir has thus the potential to thrive under warm Mediterranean conditions.ISSN:0378-1127ISSN:1872-704

    sodium calcium exchanger as main effector of endogenous neuroprotection elicited by ischemic tolerance

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    Abstract The ischemic tolerance (IT) paradigm represents a fundamental cell response to certain types or injury able to render an organ more "tolerant" to a subsequent, stronger, insult. During the 16th century, the toxicologist Paracelsus described for the first time the possibility that a noxious event might determine a state of tolerance. This finding was summarized in one of his most important mentions: "The dose makes the poison". In more recent years, ischemic tolerance in the brain was first described in 1991, when it was demonstrated by Kirino and collaborators that two minutes of subthreshold brain ischemia in gerbils produced tolerance against global brain ischemia. Based on the time in which the conditioning stimulus is applied, it is possible to define preconditioning, perconditioning and postconditioning, when the subthreshold insult is applied before, during or after the ischemic event, respectively. Furthermore, depending on the temporal delay from the ischemic event, two different modalities are distinguished: rapid or delayed preconditioning and postconditioning. Finally, the circumstance in which the conditioning stimulus is applied on an organ distant from the brain is referred as remote conditioning. Over the years the "conditioning" paradigm has been applied to several brain disorders and a number of molecular mechanisms taking part to these protective processes have been described. The mechanisms are usually classified in three distinct categories identified as triggers, mediators and effectors. As concerns the putative effectors, it has been hypothesized that brain cells appear to have the ability to adapt to hypoxia by reducing their energy demand through modulation of ion channels and transporters, which delays anoxic depolarization. The purpose of the present review is to summarize the role played by plasmamembrane proteins able to control ionic homeostasis in mediating protection elicited by brain conditioning, particular attention will be deserved to the role played by Na+/Ca2+ exchanger

    Seismic Damage Mechanisms for Churches and Damage Sequence: Considerations from a Case Study

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    Several high-intensity earthquakes have occurred in Italy in the last decades, causing considerable damage to architectural heritage and pointing out the particularly high seismic vulnerability of masonry churches. A significant research effort has been devoted to develop specific methods for the damage analysis and the seismic vulnerability assessment of these assets. An abacus of damage mechanisms recurring in the church structural components has been developed and has become an important reference in rapid assessment procedures as well as in more detailed analyses. In this perspective, the damage occurred to a church during the Pianura Padana Emiliana (Emilia) Earthquake of 2012 is analyzed here. The damage pattern reproduced, indeed, situations listed in the abacus of mechanisms. The seismic response of the church has been analyzed with different numerical approaches, with complete and with partial models that have allowed an appreciable understanding of the global behavior and of the modality of damage progressing into the mechanisms. The use of vector graphics software tools for 3D modelling that have become available in recent times has allowed to thoroughly understand the constructional complexity of the asset and, consequently, to develop simpler but structurally significant models for numerical analysis

    Changes in the expression of extracellular regulated kinase (ERK 1/2) in the R6/2 mouse model of Huntington's disease after phosphodiesterase IV inhibition

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    The mitogen-activated protein kinases (MAPKs) superfamily comprises three major signaling pathways: the extracellular signal-regulated protein kinases (ERKs), the c-Jun N-terminal kinases or stress-activated protein kinases (JNKs/SAPKs) and the p38 family of kinases.ERK 1/2 signaling has been implicated in a number of neurodegenerative disorders, including Huntington's disease (HD). Phosphorylation patterns of ERK 1/2 and JNK are altered in cell models of HD. In this study, we aimed at studying the correlations between ERK 1/2 and the neuronal vulnerability to HD degeneration in the R6/2 transgenic mouse model of HD. Single and double-label immunofluorescence for phospho-ERK (pERK, the activated form of ERK) and for each of the striatal neuronal markers were employed on perfusion-fixed brain sections from R6/2 and wild-type mice. Moreover, Phosphodiesterase 4 inhibition through rolipram was used to study the effects on pERK expression in the different types of striatal neurons. We completed our study with western blot analysis. Our study shows that pERK levels increase with age in the medium spiny striatal neurons and in the parvalbumin interneurons, and that rolipram counteracts such increase in pERK. Conversely, cholinergic and somatostatinergic interneurons of the striatum contain higher levels of pERK in the R6/2 mice compared to the controls. Rolipram induces an increase in pERK expression in these interneurons. Thus, our study confirms and extends the concept that the expression of phosphorylated ERK 1/2 is related to neuronal vulnerability and is implicated in the pathophysiology of cell death in HD. (C) 2012 Elsevier Inc. All rights reserved

    miR135a administration ameliorates brain ischemic damage by preventing TRPM7 activation during brain ischemia

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    Background: miRNA-based strategies have recently emerged as a promising therapeutic approach in several neurodegenerative diseases. Unregulated cation influx is implicated in several cellular mechanisms underlying neural cell death during ischemia. The brain constitutively active isoform of transient receptor potential melastatin 7 (TRPM7) represents a glutamate excitotoxicity-independent pathway that significantly contributes to the pathological Ca2+ overload during ischemia. Aims: In the light of these premises, inhibition of TRPM7 may be a reasonable strategy to reduce ischemic injury. Since TRPM7 is a putative target of miRNA135a, the aim of the present paper was to evaluate the role played by miRNA135a in cerebral ischemia. Therefore, the specific objectives of the present paper were: (1) to evaluate miR135a expression in temporoparietal cortex of ischemic rats; (2) to investigate the effect of the intracerebroventricular (icv) infusion of miR135a on ischemic damage and neurological functions; and (3) to verify whether miR135a effects may be mediated by an alteration of TRPM7 expression. Methods: miR135a expression was evaluated by RT- PCR and FISH assay in temporoparietal cortex of ischemic rats. Ischemic volume and neurological functions were determined in rats subjected to transient middle cerebral artery occlusion (tMCAo) after miR135a intracerebroventricular perfusion. Target analysis was performed by Western blot. Results: Our results demonstrated that, in brain cortex, 72 h after ischemia, miR135a expression increased, while TRPM7 expression was parallelly downregulated. Interestingly, miR135a icv perfusion strongly ameliorated the ischemic damage and improved neurological functions, and downregulated TRPM7 protein levels. Conclusions: The early prevention of TRPM7 activation is protective during brain ischemia

    Prolonged NCX activation prevents SOD1 accumulation, reduces neuroinflammation, ameliorates motor behavior and prolongs survival in a ALS mouse model

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    Imbalance in cellular ionic homeostasis is a hallmark of several neurodegenerative diseases including Amyotrophic Lateral Sclerosis (ALS). Sodium-calcium exchanger (NCX) is a membrane antiporter that, operating in a bidirectional way, couples the exchange of Ca2+ and Na + ions in neurons and glial cells, thus controlling the intracellular homeostasis of these ions. Among the three NCX genes, NCX1 and NCX2 are widely expressed within the CNS, while NCX3 is present only in skeletal muscles and at lower levels of expression in selected brain regions. ALS mice showed a reduction in the expression and activity of NCX1 and NCX2 consistent with disease progression, therefore we aimed to investigate their role in ALS pathophysiology. Notably, we demonstrated that the pharmacological activation of NCX1 and NCX2 by the prolonged treatment of SOD1G93A mice with the newly synthesized compound neurounina: (1) prevented the reduction in NCX activity observed in spinal cord; (2) preserved motor neurons survival in the ventral spinal horn of SOD1G93A mice; (3) prevented the spinal cord accumulation of misfolded SOD1; (4) reduced astroglia and microglia activation and spared the resident microglia cells in the spinal cord; (5) improved the lifespan and mitigated motor symptoms of ALS mice. The present study highlights the significant role of NCX1 and NCX2 in the pathophysiology of this neurodegenerative disorder and paves the way for the design of a new pharmacological approach for ALS

    Immunopathogenesis of rheumatoid arthritis

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    Rheumatoid arthritis (RA) is the most common inflammatory arthropathy. The majority of evidence, derived from genetics, tissue analyses, models, and clinical studies, points to an immune-mediated etiology associated with stromal tissue dysregulation that together propogate chronic inflammation and articular destruction. A pre-RA phase lasting months to years may be characterized by the presence of circulating autoantibodies, increasing concentration and range of inflammatory cytokines and chemokines, and altered metabolism. Clinical disease onset comprises synovitis and systemic comorbidities affecting the vasculature, metabolism, and bone. Targeted immune therapeutics and aggressive treatment strategies have substantially improved clinical outcomes and informed pathogenetic understanding, but no cure as yet exists. Herein we review recent data that support intriguing models of disease pathogenesis. They allude to the possibility of restoration of immunologic homeostasis and thus a state of tolerance associated with drug-free remission. This target represents a bold vision for the future of RA therapeutics

    Anti-CCP2 Antibodies: An Overview and Perspective of the Diagnostic Abilities of this Serological Marker for Early Rheumatoid Arthritis

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    The literature of the last 4 years confirms that the anti-CCP2 test is a very useful marker for the early and specific diagnosis of rheumatoid arthritis (RA). The anti-CCP2 test is very specific for RA (95–99%) and has sensitivity comparable to that of the rheumatoid factor (70–75%). The antibodies can be detected very early in the disease and can be used as an indicator for the progression and prognosis of RA. In this review, these interesting properties and some future possibilities of this diagnostic test are discussed

    Citrullinated histone H3 as a novel prognostic blood marker in patients with advanced cancer

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    Citrullinated histone H3 (H3Cit) is a central player in the neutrophil release of nuclear chromatin, known as neutrophil extracellular traps (NETs). NETs have been shown to elicit harmful effects on the host, and were recently proposed to promote tumor progression and spread. Here we report significant elevations of plasma H3Cit in patients with advanced cancer compared with age-matched healthy individuals. These elevations were specific to cancer patients as no increase was observed in severely ill and hospitalized patients with a higher non-malignant comorbidity. The analysis of neutrophils from cancer patients showed a higher proportion of neutrophils positive for intracellular H3Cit compared to severely ill patients. Moreover, the presence of plasma H3Cit in cancer patients strongly correlated with neutrophil activation markers neutrophil elastase (NE) and myeloperoxidase (MPO), and the inflammatory cytokines interleukin-6 and -8, known to induce NETosis. In addition, we show that high levels of circulating H3Cit strongly predicted poor clinical outcome in our cohort of cancer patients with a 2-fold increased risk for short-term mortality. Our results also corroborate the association of NE, interleukin-6 and -8 with poor clinical outcome. Taken together, our results are the first to unveil H3Cit as a potential diagnostic and prognostic blood marker associated with an exacerbated inflammatory response in patients with advanced cancer
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