126 research outputs found

    Potentially toxic elements distribution in the serpentinized and deformed ultramafic rocks from the Voltri Massif (NW, Italy)

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    The aim of the work is to assess the role of local-scale lithological, textural, and structural factors in the distribution of potentially toxic elements (PTEs) in different ultramafic rocks from the high-pressure ophiolitic Voltri Massif (Central Liguria, NW Italy). The results evidenced that Cr (up to 4183 ppm), Ni (up to 3900 ppm), and Co (up to 334 ppm) are invariably the PTEs with the highest concentrations; in addition, V, Cu, and Zn are systematically found in non-negligible amounts. Spinel-group minerals (chromium spinel, ferrian chromite, chromium magnetite, and magnetite) are by far the main potential source of the PTEs. Nevertheless, several PTEs are also present within serpentines, olivines, pyroxenes, chlorites, as well as within accessory phases (e.g., ilmenite and Ni-sulphides) and within authigenic minerals formed in the early stages of rock weathering (cryptocrystalline to amorphous Fe-oxides and -oxyhydroxides). The result obtained allowed to evidence that the main factors controlling the PTEs distribution within the rocks resulted to be the serpentinization degree and the deformation style and intensity which, in turn, strictly control the mineral assemblages and the mineral chemistry

    Primary and authigenic minerals in serpentine soils under temperate climate conditions: source or trap for potentially toxic elements (PTEs)

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    In this study, we have analysed the mineralogy and the crystal chemistry of serpentine soils from ultramafic rocks of the metaophiolitic Voltri Massif (Liguria, Italy), in order to determine the primary and authigenic mineral species controlling the distribution and the mobility of PTEs during pedogenic processes. These serpentine soils were characterised by PTEs contents commonly exceeding the concentration limits laid down by environmental agencies, particularly for Cr (1200-2500 mg/kg) and Ni (1000-4200 mg/kg). With these hazardous PTEs concentrations, the knowledge of the distribution of PTEs-bearing minerals is of paramount importance for understanding their origin and their fate during the development of serpentine soil profiles and can allow to evaluate their effective bioavailability. All the studied soil profiles were restricted in depth (10-50 cm) and showed a low degree of maturity with weakly developed A-C horizons. Soil samples were subdivided into three aliquots in order to separate the soil skeleton (2 mm-63 \u3bc m) from the silt (63-2 \u3bc m) and clay fraction (<2 \u3bc m). Quantitative mineralogical analyses were performed in all aliquots by using XRPD data collected with synchrotron sources at the MCX beamline (ELETTRA - Synchrotron, Trieste, Italy) and refined with EXP-GUI GSAS software. Trace metals were determined with energy and wavelength electron microscopy. The mineralogy of the coarse and silty fractions was closely related to bedrock mineralogy. The following minerals were detected in decreasing order of abundance: antigorite, chlorite, tremolite, magnetite, Cr-rich spinel, chrysotile, ilmenite, clinopyroxenes, olivine. Allochthonous quartz and albite were always present as minor to trace constituents. The clay fraction was mainly composed by Fe-oxides and -oxyhydroxides (mainly hematite and goethite) with subordinate amounts of mixed-layer clay minerals (chlorite-smectite, chlorite-vermiculite). These authigenic secondary minerals were characterised by poor crystallinity, intimate intergrowths, and fine-scale heterogeneities. PTEs were hosted mainly in the residual primary minerals deriving from the underlying parent material and subordinately in secondary authigenic phases. Cr was mainly contained within spinels (magnetite, Cr-magnetite, ferrichromite, picotite, and hercynite), antigorite, diopside and augite. Nonnegligible amounts of Cr was also present in authigenic hematite (up to 0.1 wt%) and goethite (up to 0.15 wt%). The main Ni-bearing minerals were olivine and antigorite but significant Ni concentration was also detected in authigenic hematite (up to 2.8 wt%) and goethite (up to 4.2 wt%) which thus represented effective traps for Ni leached through mineral weathering to the soils solution. These results are the preliminary step for the evaluation of the role of mineral species in controlling the PTEs mobility during the evolution of serpentine soil profiles. Quantitative mineralogical data will be further used to perform mass balance calculations as well as to interpret and model the results of batch leaching experiments that will be conducted on the different soil fractions

    Potentially Toxic Elements in Ultramafic Soils: A Study from Metamorphic Ophiolites of the Voltri Massif (Western Alps, Italy)

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    Ultramafic soils are characterized by severe edaphic conditions induced by a low content of essential nutrients, an adverse Ca/Mg ratio, a low water-holding capacity, and high contents of geogenic potentially toxic elements (PTEs), in particular Cr, Ni, and Co. These metals commonly exceed the content limits set by environmental agencies and governments, representing serious environmental risks for ecosystems and human health. In alpine environments, ultramafic soils are characterized by modest thickness and poor horizon differentiation. Several studies on ultramafic soils have shown that their properties may be directly related to the characteristics of the parent rocks, but most of these studies deal with soil chemistry, metal availability, isotopic composition, and pedological characterization. The aim of this research is to investigate how much the geotectonic characteristics of ultramafic bedrocks, such as the degree of serpentinization, metamorphic imprint, and deformation, may affect the mineralogical and chemical variations of ultramafic soils, including the occurrence and potential mobility of the PTEs. Using a multiscale and multi-analytical approach, we fully characterize the properties and mineralogical composition of soil profiles with different ultramafic parent rocks, i.e., partially serpentinized peridotite, massive serpentinites, and foliated serpentinites, sampled within the Voltri Massif High Pressure\u2013 Low Temperature (HP\u2013LT) metaophiolite (Western Alps, Italy). Our results, related to soils located at comparable latitude, altitude, landscape position, and pedological environment, outline that the degree of serpentinization, the metamorphic imprint, and the deformation history of the ultramafic parent rocks are key factors influencing soil evolution, mineralogy, and chemistry, as well as PTEs distribution and mobility. Moreover, this study shows that the high content of Cr, Ni, and Co in the studied ultramafic soils has to be considered of geogenic origin and highlights the need for new approaches and methods to obtain indications on the potential contamination of natural or anthropogenic soils

    Evaluation of Surgical Outcome in Rhinoplasty: A Comparison Between Rasp and Osteotome in Dorsal Hump Removal:

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    Dorsal hump reduction is a crucial point of rhinoplasty, as it has a great impact on the final shape of nasal pyramid. Depending on morphological features of the hump, its removal is usually obtained by the use of an osteotome or a rasp. In our study, we describe a closed rhinoplasty technique performed in 2 groups of patients: the only difference between the groups is the surgical tools used during the dorsal hump removal phase (rasp vs the 5-mm osteotome).We used 2 questionnaires of quality of life (QoL), Nasal Obstruction Symptom Evaluation (NOSE), and Rhinoplasty Outcome Evaluation (ROE) questionnaire, to evaluate postoperative outcome (6 months after surgery).Closed rhinoplasty was performed in 107 patients. Dorsal hump removal was carried out with rasp on 35 patients; while in 72 cases, it was performed using a 5-mm osteotome. All the patients were given 2 copies of NOSE and ROE questionnaires (1 month before surgery and 6 months after surgery) to evaluate postoperative QoL. In our study emerged that the use of osteotome in dorsal hump reduction is associated with a better aesthetic outcome (evaluated by analyzing patients QoL with ROE questionnaire) without any difference between the 2 groups in terms of functional outcome (expressed by NOSE questionnaire), major and minor complications and surgical procedure duration

    Is autopsy tissue a valid control for epilepsy surgery tissue in microRNA studies?

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    MicroRNAs (miRNAs) are differentially expressed in the brain under pathologic conditions and may therefore represent both therapeutic targets and diagnostic or prognostic biomarkers for neurologic diseases, including epilepsy. In fact, miRNA expression profiles have been investigated in the hippocampi of patients with epilepsy in comparison with control, nonepileptic cases. Unfortunately, the interpretation of these data is difficult because surgically resected epileptic tissue is generally compared with control tissue obtained from autopsies. To challenge the validity of this approach, we performed an miRNA microarray on the laser microdissected granule cell layer of the human hippocampus obtained from surgical samples of patients with epilepsy, autoptic nonepileptic controls, and patients with autoptic epilepsy, using the latter as internal control. Unfortunately, it is extremely difficult to collect autopsy material from documented epilepsy individuals who died of non–epilepsy-related causes—we found only two such cases. However, hierarchical clustering of all samples showed that those obtained from autopsies of patients with epilepsy segregated with the other autoptic samples (controls) and not with the bioptic tissues from the surgery patients, suggesting that the origin of the tissue (surgery or autopsy) may be prevalent over the underlying pathology (epilepsy or not epilepsy). Even taking into account the limitations due to the small number of cases, this observation arises concerns on the use of autopsy tissue as control for this kind of studies

    Ibrutinib modifies the function of monocyte/macrophage population in chronic lymphocytic leukemia

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    In lymphoid organs, nurse-like cells (NLCs) show properties of tumor-associated macrophages, playing a crucial role in chronic lymphocytic leukemia (CLL) cell survival. Ibrutinib, a potent inhibitor of Bruton's tyrosine kinase (BTK), is able to counteract pro-survival signals in CLL cells. Since the effects on CLL cells have been studied in the last years, less is known about the influence of ibrutinib on NLCs properties. We sought to determine how ibrutinib modifies NLCs functions focusing on the balance between immunosuppressive and inflammatory features. Our data show that ibrutinib targets BTK expressed by NLCs modifying their phenotype and function. Treatment with ibrutinib reduces the phagocytic ability and increases the immunosuppressive profile of NLCs exacerbating the expression of M2 markers. Accordingly, ibrutinib hampers LPS-mediated signaling, decreasing STAT1 phosphorylation, while allows IL-4-mediated STAT6 phosphorylation. In addition, NLCs treated with ibrutinib are able to protect CLL cells from drug-induced apoptosis partially through the secretion of IL-10. Results from patient samples obtained prior and after 1 month of treatment with ibrutinib show an accentuation of CD206, CD11b and Tie2 in the monocytic population in the peripheral blood. Our study provides new insights into the immunomodulatory action of ibrutinib on monocyte/macrophage population in CLL

    Deletion of the Virion Host Shut-off Gene Enhances Neuronal-Selective Transgene Expression from an HSV Vector Lacking Functional IE Genes

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    The ability of herpes simplex virus (HSV) to establish lifelong latency in neurons suggests that HSV-derived vectors hold promise for gene delivery to the nervous system. However, vector toxicity and transgene silencing have created significant barriers to vector applications to the brain. Recently, we described a vector defective for all immediate-early gene expression and deleted for the joint region between the two unique genome segments that proved capable of extended transgene expression in non-neuronal cells. Sustained expression required the proximity of boundary elements from the latency locus. As confirmed here, we have also found that a transgene cassette introduced into the ICP4 locus is highly active in neurons but silent in primary fibroblasts. Remarkably, we observed that removal of the virion host shutoff (vhs) gene further improved transgene expression in neurons without inducing expression of viral genes. In rat hippocampus, the vhs-deleted vector showed robust transgene expression exclusively in neurons for at least 1 month without evidence of toxicity or inflammation. This HSV vector design holds promise for gene delivery to the brain, including durable expression of large or complex transgene cassettes

    Lenalidomide interferes with tumor-promoting properties of nurse-like cells in chronic lymphocytic leukemia

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    Lenalidomide is an immunomodulatory agent clinically active in chronic lymphocytic leukemia patients. The specific mechanism of action is still undefined, but includes modulation of the microenvironment. In chronic lymphocytic leukemia patients, nurse-like cells differentiate from CD14(+) mononuclear cells and protect chronic lymphocytic leukemia cells from apoptosis. Nurse-like cells resemble M2 macrophages with potent immunosuppressive functions. Here, we examined the effect of lenalidomide on the monocyte/macrophage population in chronic lymphocytic leukemia patients. We found that lenalidomide induces high actin polymerization on CD14(+) monocytes through activation of small GTPases, RhoA, Rac1 and Rap1 that correlated with increased adhesion and impaired monocyte migration in response to CCL2, CCL3 and CXCL12. We observed that lenalidomide increases the number of nurse-like cells that lost the ability to nurture chronic lymphocytic leukemia cells, acquired properties of phagocytosis and promoted T-cell proliferation. Gene expression signature, induced by lenalidomide in nurse-like cells, indicated a reduction of pivotal pro-survival signals for chronic lymphocytic leukemia, such as CCL2, IGF1, CXCL12, HGF1, and supported a modulation towards M1 phenotype with high IL2 and low IL10, IL8 and CD163. Our data provide new insights into the mechanism of action of lenalidomide that mediates a pro-inflammatory switch of nurse-like cells affecting the protective microenvironment generated by chronic lymphocytic leukemia into tissues

    Hippocampal FGF-2 and BDNF overexpression attenuates epileptogenesis-associated neuroinflammation and reduces spontaneous recurrent seizures

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    Under certain experimental conditions, neurotrophic factors may reduce epileptogenesis. We have previously reported that local, intrahippocampal supplementation of fibroblast growth factor-2 (FGF-2) and brain-derived neurotrophic factor (BDNF) increases neurogenesis, reduces neuronal loss, and reduces the occurrence of spontaneous seizures in a model of damage-associated epilepsy. Here, we asked if these possibly anti-epileptogenic effects might involve anti-inflammatory mechanisms. Thus, we used a Herpes-based vector to supplement FGF-2 and BDNF in rat hippocampus after pilocarpine-induced status epilepticus that established an epileptogenic lesion. This model causes intense neuroinflammation, especially in the phase that precedes the occurrence of spontaneous seizures. The supplementation of FGF-2 and BDNF attenuated various parameters of inflammation, including astrocytosis, microcytosis and IL-1β expression. The effect appeared to be most prominent on IL-1β, whose expression was almost completely prevented. Further studies will be needed to elucidate the molecular mechanism(s) for these effects, and for that on IL-1β in particular. Nonetheless, the concept that neurotrophic factors affect neuroinflammation in vivo may be highly relevant for the understanding of the epileptogenic process
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