55 research outputs found
MICROPILES TRIPODS SHIELDS (MTS) AS UNCONVENTIONAL BREAKERS FOR THE CONTROL OF MODERATELY RAPID EARTHFLOWS (SASSI NERI LANDSLIDE, NORTHERN APENNINES)
The paper deals with the idea, design and implementation of unconventional one-of-a-kind Micropiles Tripods Shields (MTS) intended to break and decelerate moderately rapid earthflows surges in the track zone of the Sassi Neri landslide (Nure Valley, Northern Apennines, Province of Piacenza, Italy). The MTS are inspired to floating anchors and âchevaux de friesâ used in wartime. The basic elements are tripods of 193 mm diameter steel micropiles laid out at triangle, driven into the stable bedrock and emerging some meters aboveground. Each tripod consists of a vertical upslope central pile and two lateral oblique piles, linked by two transversal beams and connection plates aboveground. Multiple tripods are spaced along transversal rows to form Micropiles Tripods Shields (MTS) to advancing earthflows. The design of MTS has been based on field investigations such as boreholes and geophysics, that indicated a limited thickness of landslide deposits in the track zone where MTS have been installed. The forces resulting from active earthflows fronts have been estimated both with geotechnical and hydraulic computations. The analysis of vertical and transversal forces as well as bending moments acting on a single tripod versus the characteristic resistances was carried out using a bi-dimensional scheme with finite-elements software Plaxis, that indicated that the stress levels were compatible with the structural resistance of the tripods. The construction of MTS took place in 2018, involving working site preparation with partial lime-treatment of the surficial layers, underground micropiles drilling and installation, aboveground micropiles welding, tripods completion with connection beams and plates. Some tripods have been instrumented with load cells for monitoring earth pressures against micropiles, electric transducers for groundwater monitoring next to the piles, tiltmeters for tripods rotations and a total station for slope and tripods movements monitoring. Results show that the acceleration of slope movements corresponds to a generalized increase of pore water pressure at all the monitored tripods and to temporary slight tilting of the tripods which has so far being fully recovered when the landside slowed down and pressure decreased. This pioneering application indicates that once the characteristics of the earthflows are carefully considered, the depth to the bedrock in the installation zone is limited, and the logistical conditions in the field during construction are adequate, the MTS can be taken into consideration as a possible unconventional solution to break down and control moderately rapid earthflows
Co-Transplantation of endothelial progenitor cells and pancreatic islets to induce long-lasting normoglycemia in streptozotocin-treated diabetic rats
Graft vascularization is a crucial step to obtain stable normoglycemia in pancreatic islet transplantation. Endothelial progenitor cells (EPCs) contribute to neoangiogenesis and to the revascularization process during ischaemic events and play a key role in the response to pancreatic islet injury. In this work we co-transplanted EPCs and islets in the portal vein of chemically-induced diabetic rats to restore islet vascularization and to improve graft survival. Syngenic islets were transplanted, either alone or with EPCs derived from green fluorescent protein (GFP) transgenic rats, into the portal vein of streptozotocin-induced diabetic rats. Blood glucose levels were monitored and intraperitoneal glucose tolerance tests were performed. Real time-PCR was carried out to evaluate the gene expression of angiogenic factors. Diabetic-induced rats showed long-lasting (6 months) normoglycemia upon co-transplantation of syngenic islets and EPCs. After 3â5 days from transplantation, hyperglycaemic levels dropped to normal values and lasted unmodified as long as they were checked. Further, glucose tolerance tests revealed the animals' ability to produce insulin on-demand as indexed by a prompt response in blood glucose clearance. Graft neovascularization was evaluated by immunohistochemistry: for the first time the measure of endothelial thickness revealed a donor-EPC-related neovascularization supporting viable islets up to six months after transplant. Our results highlight the importance of a newly formed viable vascular network together with pancreatic islets to provide de novo adequate supply in order to obtain enduring normoglycemia and prevent diabetes-related long-term health hazards
Simultaneous Golgi-Cox and immunofluorescence using confocal microscopy
Visualization of neuronal elements is of fundamental
importance in modern neuroscience. Golgi-Cox
impregnation is a widely employed method that provides
detailed information about morphological characteristics of
neurons, but none regarding their neurochemical features.
Immunocytochemical procedures, on the other hand, can
provide a high degree of biochemical specificity but poorer
morphological details, in particular if compared to Golgi-
Cox impregnation. Hence, the combined use of these two
approaches is highly desirable, especially for confocal
microscopy that can exploit the advantages of both methods
simultaneously. Here we show an innovative procedure
of perfusion and fixation of brain tissue, that allows, by
applying Golgi-Cox impregnation and immunofluorescence
in the same histological section, to obtain high-quality histological material, with a very simple and inexpensive
method. This procedure is based on three simple fixation
steps: (1) a paraformaldehyde perfusion followed by a standard post-fixation to stabilize the subsequent immunofluorescence reaction; (2) the classical Golgi-Cox impregnation and (3) an immunofluorescence reaction in previously impregnated material. This combination allows simultaneous visualization of (a) the structural details (Golgi-Cox impregnated neurons), (b) the antigensâ characterization, (c) the anatomical interactions between discrete neuronal elements and (d) the 3D reconstruction and modeling. The method is easy to perform and can be reproducibly applied by small laboratories and expanded through the use of different antibodies. Overall, the method presented in this study offers an innovative and powerful approach to study the nervous system, especially by using confocal microscopy
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Modeling Parkinson's Disease Neuropathology and Symptoms by Intranigral Inoculation of Preformed Human α-Synuclein Oligomers.
The accumulation of aggregated α-synuclein (αSyn) is a hallmark of Parkinson's disease (PD). Current evidence indicates that small soluble αSyn oligomers (αSynOs) are the most toxic species among the forms of αSyn aggregates, and that size and topological structural properties are crucial factors for αSynOs-mediated toxicity, involving the interaction with either neurons or glial cells. We previously characterized a human αSynO (H-αSynO) with specific structural properties promoting toxicity against neuronal membranes. Here, we tested the neurotoxic potential of these H-αSynOs in vivo, in relation to the neuropathological and symptomatic features of PD. The H-αSynOs were unilaterally infused into the rat substantia nigra pars compacta (SNpc). Phosphorylated αSyn (p129-αSyn), reactive microglia, and cytokine levels were measured at progressive time points. Additionally, a phagocytosis assay in vitro was performed after microglia pre-exposure to αsynOs. Dopaminergic loss, motor, and cognitive performances were assessed. H-αSynOs triggered p129-αSyn deposition in SNpc neurons and microglia and spread to the striatum. Early and persistent neuroinflammatory responses were induced in the SNpc. In vitro, H-αSynOs inhibited the phagocytic function of microglia. H-αsynOs-infused rats displayed early mitochondrial loss and abnormalities in SNpc neurons, followed by a gradual nigrostriatal dopaminergic loss, associated with motor and cognitive impairment. The intracerebral inoculation of structurally characterized H-αSynOs provides a model of progressive PD neuropathology in rats, which will be helpful for testing neuroprotective therapies
Prognostic Factors for Overall Survival In Chronic Myeloid Leukemia Patients: A Multicentric Cohort Study by the Italian CML GIMEMA Network
An observational prospective study was conducted by the CML Italian network to analyze the role of baseline patient characteristics and first line treatments on overall survival and CML-related mortality in 1206 newly diagnosed CML patients, 608 treated with imatinib (IMA) and 598 with 2nd generation tyrosine kinase inhibitors (2GTKI). IMA-treated patients were much older (median age 69 years, IQR 58-77) than the 2GTKI group (52, IQR 41-63) and had more comorbidities. Estimated 4-year overall survival of the entire cohort was 89% (95%CI 85.9-91.4). Overall, 73 patients (6.1%) died: 17 (2.8%) in the 2GTKI vs 56 (9.2%) in the IMA cohort (adjusted HR=0.50; 95% CI=0.26-0.94), but no differences were detected for CML-related mortality (10 (1.7%) vs 11 (1.8%) in the 2GTKIs vs IMA cohort (sHR=1.61; 0.52-4.96). The ELTS score was associated to CML mortality (high risk vs low, HR=9.67; 95%CI 2.94-31.74; p<0.001), while age (per year, HR=1.03; 95%CI 1.00-1.06; p=0.064), CCI (4-5 vs 2, HR=5.22; 95%CI 2.56-10.65; p<0.001), ELTS score (high risk vs low, HR=3.11; 95%CI 1.52-6.35, p=0.002) and 2GTKI vs IMA (HR=0.26; 95%CI 0.10-0.65, p=0.004) were associated to an increased risk of non-related CML mortality. The ELTS score showed a better discriminant ability than the Sokal score in all comparisons
Variants within the immunoregulatory CBLB gene are associated with multiple sclerosis
A genome wide association scan of ~6.6 million genotyped or imputed variants in 882 Sardinian Multiple Sclerosis (MS) cases and 872 controls suggested association of CBLB gene variants with disease, which was confirmed in 1,775 cases and 2,005 controls (overall P =1.60 Ă 10-10). CBLB encodes a negative regulator of adaptive immune responses and mice lacking the orthologue are prone to experimental autoimmune encephalomyelitis, the animal model of MS
Overexpression of the Cytokine BAFF and Autoimmunity Risk
: Genomewide association studies of autoimmune diseases have mapped hundreds of susceptibility regions in the genome. However, only for a few association signals has the causal gene been identified, and for even fewer have the causal variant and underlying mechanism been defined. Coincident associations of DNA variants affecting both the risk of autoimmune disease and quantitative immune variables provide an informative route to explore disease mechanisms and drug-targetable pathways.
: Using case-control samples from Sardinia, Italy, we performed a genomewide association study in multiple sclerosis followed by TNFSF13B locus-specific association testing in systemic lupus erythematosus (SLE). Extensive phenotyping of quantitative immune variables, sequence-based fine mapping, cross-population and cross-phenotype analyses, and gene-expression studies were used to identify the causal variant and elucidate its mechanism of action. Signatures of positive selection were also investigated.
: A variant in TNFSF13B, encoding the cytokine and drug target B-cell activating factor (BAFF), was associated with multiple sclerosis as well as SLE. The disease-risk allele was also associated with up-regulated humoral immunity through increased levels of soluble BAFF, B lymphocytes, and immunoglobulins. The causal variant was identified: an insertion-deletion variant, GCTGTâA (in which A is the risk allele), yielded a shorter transcript that escaped microRNA inhibition and increased production of soluble BAFF, which in turn up-regulated humoral immunity. Population genetic signatures indicated that this autoimmunity variant has been evolutionarily advantageous, most likely by augmenting resistance to malaria.
: A TNFSF13B variant was associated with multiple sclerosis and SLE, and its effects were clarified at the population, cellular, and molecular levels. (Funded by the Italian Foundation for Multiple Sclerosis and others.).Supported by grants (2011/R/13 and 2015/R/09, to Dr. Cucca) from the Italian Foundation for Multiple Sclerosis; contracts (N01-AG-1-2109 and HHSN271201100005C, to Dr. Cucca) from the Intramural Research Program of the National Institute on Aging, National Institutes of Health (NIH); a grant (FaReBio2011 âFarmaci e Reti Biotecnologiche di QualitĂ ,â to Dr. Cucca) from the Italian Ministry of Economy and Finance; a grant (633964, to Dr. Cucca) from the Horizon 2020 Research and Innovation Program of the European Union; a grant (U1301.2015/AI.1157.BE Prat. 2015-1651, to Dr. Cucca) from Fondazione di Sardegna; grants (âCentro per la ricerca di nuovi farmaci per malattie rare, trascurate e della povertĂ â and âProgetto collezione di composti chimici ed attivitĂ di screening,â to Dr. Cucca) from Ministero dellâIstruzione, dellâUniversitĂ e della Ricerca; grants (HG005581, HG005552, HG006513, and HG007022, to Dr. Abecasis) from the National Human Genome Research Institute; a grant (9-2011-253, to Dr. Todd) from JDRF; a grant (091157, to Dr. Todd) from the Wellcome Trust; a grant (to Dr. Todd) from the National Institute for Health Research (NIHR); and the NIHR Cambridge Biomedical Research Centre. Dr. Idda was a recipient of a Master and Back fellowship from the Autonomous Region of Sardinia
Microglial phenotypes in Parkinson's disease and animal models of the disease
Over the last decade the important concept has emerged that microglia, similar to other tissue macrophages, assume different phenotypes and serve several effector functions, generating the theory that activated microglia can be organized by their pro-inflammatory or anti-inflammatory and repairing functions. Importantly, microglia exist in a heterogenous population and their phenotypes are not permanently polarized into two categories; they exist along a continuum where they acquire different profiles based on their local environment. In Parkinson's disease (PD), neuroinflammation and microglia activation are considered neuropathological hallmarks, however their precise role in relation to disease progression is not clear, yet represent a critical challenge in the search of disease-modifying strategies. This review will critically address current knowledge on the activation states of microglia as well as microglial phenotypes found in PD and in animal models of PD, focusing on the expression of surface molecules as well as pro-inflammatory and anti-inflammatory cytokine production during the disease process. While human studies have reported an elevation of both pro- or anti-inflammatory markers in the serum and CSF of PD patients, animal models have provided insights on dynamic changes of microglia phenotypes in relation to disease progression especially prior to the development of motor deficits. We also review recent evidence of malfunction at multiple steps of NFÎșB signaling that may have a causal interrelationship with pathological microglia activation in animal models of PD. Finally, we discuss the immune-modifying strategies that have been explored regarding mechanisms of chronic microglial activation
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