The Roccamonfina volcano is characterised by two stages of volcanic activity that are separated by volcano-tectonic caldera collapses. Ultrapotassic leucite-bearing rocks are confined to the ...pre-caldera stage and display geochemical characteristics similar to those of other volcanoes in the Roman Province. After the major sector collapse of the volcano, occurred at ca. 400 ka, shoshonitic rocks erupted from cinder cones and domes both within the caldera and on the external flanks of the pre-caldera Roccamonfina volcano. On the basis of new trace element and Sr–Nd–Pb isotope data, we show that the Roccamonfina shoshonitic rocks are distinct from shoshonites of the Northern Roman Province, but are very similar to those of the Neapolitan volcanoes. The last phases of volcanic activity erupted sub-alkaline magmas as enclaves in trachytic domes, and as lavas within the Monte Santa Croce dome. Ultrapotassic rocks of the pre-caldera composite volcano are plagioclase-bearing leucitites characterised by high levels of incompatible trace elements with an orogenic signature having troughs at Ba, Ta, Nb, and Ti, and peaks at Cs, K, Th, U, and Pb. Initial values of
87
Sr/
86
Sr range from 0.70926 to 0.70999,
143
Nd/
144
Nd ranges from 0.51213 to 0.51217, while the lead isotope rations vary between 18.788–18.851 for
206
Pb/
204
Pb, 15.685–15.701 for
207
Pb/
204
Pb, and 39.048–39.076 for
208
Pb/
204
Pb. Shoshonites show a similar pattern of trace element depletions and enrichments to the earlier ultrapotassic leucite-bearing rocks but have a larger degree of differentiation and lower concentrations of incompatible trace elements. On the other hand, shoshonitic rocks have Sr, Nd, and Pb isotopes consistently different than pre-caldera ultrapotassic leucite-bearing rocks.
87
Sr/
86
Sr ranges from 0.70665 to 0.70745,
143
Nd/
144
Nd ranges from 0.51234 to 0.51238,
206
Pb/
204
Pb ranges from 18.924 to 19.153,
207
Pb/
204
Pb ranges from 15.661 to 15.694, and
208
Pb/
204
Pb ranges from 39.084 to 39.212. High-K calc-alkaline samples have intermediate isotopic values between ultrapotassic plagioclase leucitites and shoshonites, but the lowest levels of incompatible trace element contents. It is argued that ultrapotassic magmas were generated in a modified lithospheric mantle after crustal-derived metasomatism. Interaction between the metasomatic agent and lithospheric upper mantle produced a low-melting point metasomatised veined network. The partial melting of the veins alone produced pre-caldera leucite-bearing ultrapotassic magmas. It was possibly triggered by either post-collisional isotherms relaxation or increasing
T
°C due increasing heat flow through slab tears. Shoshonitic magmas were generated by further melting, at higher temperature, of the same metasomatic assemblage with addition 10–20% of OIB-like astenospheric mantle material. We suggest that addition of astenospheric upper mantle material from foreland mantle, flowing through slab tearing after collision was achieved.
A 50 m thick and 150 m long dunite body occurs as a subconcordant, tabular structure in the Balmuccia Massif, an Alpine peridotite thought to represent part of the subcontinental mantle. The contacts ...with the host spinel-facies depleted lherzolite are sharp. The dunite body is composed of spinel-rich dunite containing centimetre-size lenses of relict Cr-diopside websterite, spinel-poor granoblastic dunite and virtually monomineralic Cr-spinel layers exhibiting flow structures. Orthopyroxene is a minor, relict phase in all the lithologies; clinopyroxene is intergranular and amphibole is a minor accessory phase. Overall the dunite body is fairly refractory (Fo in olivine: 90·7–93·8). Strontium and neodymium isotope ratios of clinopyroxene separates from the dunitic body resemble those of a Cr-diopside websterite suite that forms a series of dykes cutting the main peridotite host. It is proposed that the dunites were generated in a part of the mantle veined by early Cr-diopside websterites by a three-stage process involving partial melting of pyroxenite, infiltration of the pyroxenite-derived melt into the depleted lherzolite and its consequent open-system partial melting and focused flow of the resultant partial melts leading to the production of reactive dunite channels through both peridotite and pyroxenite. This process has been simulated using pMELTS assuming that the pyroxenite partially melts at 1·5 GPa and focused melt transport occurs at pressures greater than 0·7 GPa. The results show that, depending on the focusing factor assumed, dunite can form from peridotite at P < 1·2 GPa and from pyroxenite at P < 1·1 GPa, in both cases over a large pressure range. The model accounts for specific characteristics of the dunite, such as its refractory composition, the presence of orthopyroxene relics, the occurrence of relict websterite lenses in the spinel-rich dunites and the flow structures in the Cr-spinel layers. The proposed mechanism allows dunite formation to occur well within the spinel stability field, and therefore at greater depth than dunites in ophiolites, which generally formed within the plagioclase stability field. The aggregated model melts extracted from the segments where dunite forms are high-Mg alkali basalts resembling, after olivine fractionation, the compositions of enriched-type mid-ocean ridge basalt from slow- and ultraslow-spreading ocean ridges.
The Middle Latin Valley volcanic field forms part of the Roman Magmatic Province and includes Pleistocene monogenetic volcanism characterized by the emplacement of small lava flows and minor ...pyroclastic ejecta and flows. The absence of a main volcanic edifice and of a large, shallow-level magma reservoir allows the eruption of primitive magmas. Geochemical and petrological data suggest that at least four types of mafic parental magmas are present within the volcanic field: (1) melilite-bearing ultrapotassic (kamafugitic); (2) plagioclase-bearing and -free leucititic (HKS); (3) shoshonitic; (4) sub-alkaline. 40Ar–39Ar dating reveals diachronous emplacement of mafic magmas with different levels of K enrichment; the kamafugitic lavas are the oldest and the sub-alkaline lavas the youngest. Incompatible trace element contents strictly follow K2O, but overall the groups of rocks show similar trace element fractionation, with high field strength elements less enriched than large ion lithophile elements. Despite a restricted range in MgO and SiO2 contents, the Middle Latin Valley volcanic rocks have highly variable Sr, Nd and Pb isotopic compositions. The sub-alkaline rocks have the lowest 87Sr/86Sr and the highest 143Nd/144Nd, whereas the kamafugitic rocks have the highest 87Sr/86Sr and the lowest 143Nd/144Nd. Intermediate isotopic compositions between these two end-members are shown by leucitites–plagio-leucitites and shoshonites. A clear, time-dependent trend of isotopic variation is observed. This also holds true for Pb isotope compositions, with shoshonitic and sub-alkaline rocks showing the most radiogenic signatures and the kamafugitic rocks the least radiogenic signatures. The overall geochemical characteristics of the magmas can be reconciled in terms of a model involving recycling of marly shales within the upper mantle; this overprinted earlier pervasive metasomatism related to melts (supercritical fluids) derived from altered oceanic basalts. The crustal derived (marl) end-member is considered to have been concentrated within a metasomatic vein network within the lithosphere, whereas the supercritical fluid-metasomatized end-member occurs within the surrounding mantle. Early partial melting of veins produced strongly undersaturated melilite-bearing ultrapotassic magma (kamafugitic). The progressive exhaustion of the veined mantle increased the contribution of the surrounding mantle to magma production, explaining the decrease of K2O with time in the mafic magmas and the geochemical and isotopic transition from leucititic–plagio-leucititic to shoshonitic and sub-alkaline magmas, the latter being the youngest products erupted.
The “Colli Albani” composite volcano is made up of strongly silica-undersaturated leucite-bearing rocks. Magmas were erupted during three main periods, but a complex plumbing system dominated by ...regional tectonics channelled magmas into different reservoirs. The most alkali-rich magmas, restricted to the caldera-forming period (pre-caldera), are extremely enriched in incompatible trace elements and display more radiogenic Sr (
87
Sr/
86
Sr = 0.71057–0.71067), with slightly less radiogenic Pb with respect to those of the post-caldera period. Post-caldera volcanic activity was concentrated in three different volcanic environments: external to the caldera, along the caldera edge and within the caldera. The post-caldera magmas produced melilite- to leucitite-bearing, plagioclase-free leucitites. In contrast to the pre-caldera lavas, they are characterised by lower incompatible trace element abundances and less radiogenic Sr (
87
Sr/
86
Sr = 0.71006–0.71039). Magmas evolved through crystal fractionation plus minor crustal assimilation in a large magma chamber during the pre-caldera period. The multiple caldera collapses dissected and partially obliterated the early magma chamber. During the post-caldera stage, magmas were channelled through several pathways and multiple shallow-level magma reservoirs were established. A lithospheric mantle wedge previously depleted in the basaltic component and subsequently enriched by metasomatic slab-derived component is suggested as the mantle source of Colli Albani parental magmas. Two different parental magmas are recognised for the pre- and post-caldera stages. The differences may be related to the interplay between smaller degrees of melting for the pre-caldera magmas and more carbonate-rich recycled subducted lithologies in the post-caldera magmas.
The Middle Latin Valley volcanic field forms part of the Roman Magmatic Province and includes Pleistocene monogenetic volcanism characterized by the emplacement of small lava flows and minor ...pyroclastic ejecta and flows. The absence of a main volcanic edifice and of a large, shallow-level magma reservoir allows the eruption of primitive magmas. Geochemical and petrological data suggest that at least four types of mafic parental magmas are present within the volcanic field: (1) melilite-bearing ultrapotassic (kamafugitic); (2) plagioclase-bearing and -free leucititic (HKS); (3) shoshonitic; (4) sub-alkaline. super(40)Ar- super(39)Ar dating reveals diachronous emplacement of mafic magmas with different levels of K enrichment; the kamafugitic lavas are the oldest and the sub-alkaline lavas the youngest. Incompatible trace element contents strictly follow K sub(2)O, but overall the groups of rocks show similar trace element fractionation, with high field strength elements less enriched than large ion lithophile elements. Despite a restricted range in MgO and SiO sub(2) contents, the Middle Latin Valley volcanic rocks have highly variable Sr, Nd and Pb isotopic compositions. The sub-alkaline rocks have the lowest super(87)Sr/ super(86)Sr and the highest super(143)Nd/ super(144)Nd, whereas the kamafugitic rocks have the highest super(87)Sr/ super(86)Sr and the lowest super(143)Nd/ super(144)Nd. Intermediate isotopic compositions between these two end-members are shown by leucitites-plagio-leucitites and shoshonites. A clear, time-dependent trend of isotopic variation is observed. This also holds true for Pb isotope compositions, with shoshonitic and sub-alkaline rocks showing the most radiogenic signatures and the kamafugitic rocks the least radiogenic signatures. The overall geochemical characteristics of the magmas can be reconciled in terms of a model involving recycling of marly shales within the upper mantle; this overprinted earlier pervasive metasomatism related to melts (supercritical fluids) derived from altered oceanic basalts. The crustal derived (marl) end-member is considered to have been concentrated within a metasomatic vein network within the lithosphere, whereas the supercritical fluid-metasomatized end-member occurs within the surrounding mantle. Early partial melting of veins produced strongly undersaturated melilite-bearing ultrapotassic magma (kamafugitic). The progressive exhaustion of the veined mantle increased the contribution of the surrounding mantle to magma production, explaining the decrease of K sub(2)O with time in the mafic magmas and the geochemical and isotopic transition from leucititic-plagio-leucititic to shoshonitic and sub-alkaline magmas, the latter being the youngest products erupted.
Extremely long basaltic lava flows are here presented and described. The flows originated from the great, polygenetic, fissural Payen Volcanic Complex, in the Andean back-arc volcanic province of ...Payenia in Argentina. The lava flows outpoured during the Late Quaternary from the summit rift of a shield volcano representing the first volcanic centre of this complex. One of these flows presents an individual tongue-like shape with a length of 181 km and therefore is the longest known individual Quaternary lava flow on Earth. Leaving the flanks of the volcano this flow reached the Salado river valley at La Pampa and, in its distal portion, maintained its narrow and straight shape without any topographic control over a flat alluvial plain. It has a hawaiite composition with low phenocryst content of prevailing olivine and minor plagioclase. Rare Earth element patterns are typical of Na-alkaline basalts, but incompatible trace element patterns and Sr -Nd isotope ratios, suggest a geodynamic setting transitional to the orogenic one. The flow advanced following the thermally efficient "inflation" mechanism, as demonstrated by a peculiar association of well developed morphological, structural and textural features. The temperature of 1130-1160°C and the viscosity of 3-73 Pa*s, calculated by petrochemical data, may be considered, together with a very low cooling rate and a sustained and long lasting effusion rate, the main causes of the extremely long transport system of this flow. Both the extreme length of the flow and the partial lack of topographic control may provide new constraints on the physics of large inflated flows, which constitute the largest volcanic provinces on Earth and probably also on the terrestrial planets.
Given the extensive histomorphological heterogeneity of high‐grade gliomas, in terms of extent of invasiveness, angiogenesis, and necrosis and the poor prognosis for patients despite the advancements ...made in therapeutic management. The identification of genes associated with these phenotypes will permit a better definition of glioma heterogeneity, which may ultimately lead to better treatment strategies. CXCR4, a cell surface chemokine receptor, is implicated in the growth, invasion, angiogenesis and metastasis in a wide range of malignant tumors, including gliomas. It is overexpressed in glioma cells according to tumor grade and in glioma tumor initiating cells. There have been various reports suggesting that CXCR4 is required for tumor proliferation, invasion, angiogenesis, and modulation of the immune response. It may also serve as a prognostic factor in characterizing subsets of glioblastoma multiforme, as patients with CXCR4‐positive gliomas seem to have poorer prognosis after surgery. Aim of this review was to analyze the current literature on biological effects of CXCR4 activity and its role in glioma pathogenesis. A better understanding of CXCR4 pathway in glioma will lead to further investigation of CXCR4 as a novel putative therapeutic target. GLIA 2014;62:1015–1023
Main points
The review is focused on the analysis of current literature on biological effects of CXCR4 in glioma pathogenesis. A better understanding of CXCR4 pathway in glioma will lead to further investigation of CXCR4 as a novel putative therapeutic target.
Abstract
Aim
there is evidence of significant clinical sequelae of COVID-19 that may impair both life length and its quality. Aim of this study was to assess the long-term consequences of moderate to ...severe SARS-CoV-2-related pneumonia in patients requiring high-flow oxygen treatment.
Methods
This prospective follow-up study included 45 patients with confirmed COVID-19 admitted to a medical ward at the Montichiari Hospital, Brescia, Italy from November 2020 to April 2021 Patients had COVID-19 related pneumonia with respiratory failure and needed at least treatment with an inspired fraction of oxygen of 40% (of them, 59% were treated with Venturi mask and 41% needed non-invasive ventilation). Patients underwent a clinical assessment with standard laboratory testing, chest CT scan, lung function tests with DLCO, and evaluation of vital parameters after a mean of 382 days after hospital discharge. A quality-of-life questionnaire was administered to each willing patient.
Results
See table for details. While standard laboratory testing showed a substantial normalization, we found persistence of radiological alterations (i.e. ground-glass opacities, irregular linear/reticular opacities) in 61% of patients; mean Tiffenau index (FEV1/FVC) was reduced, although not clearly pathologic (79%) and 38% of patients showed a mild to moderate reduction in CO lung diffusion (DLCO). Interestingly, 54% of subjects showed concomitant presence of radiologic alterations AND persistence of dyspnea OR reduction in CO lung diffusion, while 21% had all three concomitant conditions, compatible with the diagnosis of lung fibrosis. Overall, a total of 75% patients had some degree of functional or structural alteration of respiratory apparatus. We also evaluated quality of life thorough a structured questionnaire: after more than one year 62% of the patients still lamented fatigue, 62% effort dyspnea, 12% anorexia, 29% dysgeusia or anosmia, 31% insomnia and 43% anxiety.
Conclusions
these data seem to demonstrate that SARS-CoV-2-related pneumonia requiring high flow oxygen has a heavy long-term burden, both in terms of persistence of functional and structural pulmonary damage (which may be progressive and evolve to a more severe degree) and of burden on overall quality daily life.
OBJECTIVESpontaneously hypertensive rats are an example of an animal model of genetic hypertension with insulin resistance. The aim of this study was to investigate insulin signaling in the heart and ...in the skeletal muscle of spontaneously hypertensive rats, as well as to evaluate the effects of renin–angiotensin system blockade.
DESIGN AND METHODSWe investigated eight untreated spontaneously hypertensive rats of 12 weeks of age and eight age-matched normotensive Wistar–Kyoto controls. In addition, eight spontaneously hypertensive rats were treated for 8 weeks with the angiotensin receptor blocker olmesartan, and eight spontaneously hypertensive rats with the angiotensin-converting enzyme inhibitor enalapril. The heart and a skeletal muscle (quadriceps femoris) were promptly dissected and frozen. Insulin signaling was evaluated by Western blot analysis of involved proteins; in addition, microvessel density was indirectly evaluated by immunohistochemistry.
RESULTSBlood pressure values were normalized by both olmesartan and enalapril. In the heart, no statistically significant difference in the expression of proteins involved in insulin signaling was observed between untreated spontaneously hypertensive rats and Wistar–Kyoto controls. On the contrary, in the skeletal muscle of untreated spontaneously hypertensive rats, we noted a significant reduction of insulin receptors, of insulin-receptor substrate-1, and of phosphorylated-mammalian target of rapamycin. The treatment with olmesartan normalized insulin signaling, including expression of glucose transporter-4, whereas the treatment with enalapril was ineffective for the insulin receptor and less effective than olmesartan on the insulin-receptor substrate-1, phosphorylated-mammalian target of rapamycin and glucose transporter-4. There was a significant reduction in microvessel density in the skeletal muscle of spontaneously hypertensive rats compared with Wistar–Kyoto controls, and this was completely prevented by both olmesartan and enalapril.
CONCLUSIONThese results suggest that changes in insulin signaling occur in the skeletal muscle but not in the heart of untreated spontaneously hypertensive rats. In the skeletal muscle, insulin signaling was restored by olmesartan, whereas enalapril was less effective. Effective antihypertensive treatment with olmesartan or enalapril was associated with prevention of microvascular rarefaction.
Abstract
Introduction
The Coronavirus disease 2019 (COVID-19), doesn't affect only respiratory system, but it also involves other organs including cardiovascular system, possibly causing acute or ...chronic cardiovascular events. Preexisting cardiovascular diseases enhance COVID-19 morbidity, as well.
Aim
In this retrospective analysis we investigated the onset of cardiovascular events during a time-span of more than one year since hospitalization (384 days).
Methods
The analysis included 43 patients, who were hospitalized in Internal Medicine Department of Montichiari Hospital (ASST Spedali Civili of Brescia) for moderate to severe SARS-CoV2 related pneumonia treated with high-flow oxygen support (ranging from 40% fraction of inspired oxygen to non-invasive ventilation)
Mean age was 63 years, 28% (12/43) were female and 72% (31/43) were male. Thirty-five percent of the patients suffered from heart diseases, 56% of them were hypertensives and 23% had type 2 diabetes; 12% had chronic kidney disease (CKD) and 5% an active neoplasm. 49% of the sample was obese. Nineteen percent took ACE inhibitors and 19% was on ARBs. Statins were taken by 37% of the patients; an antiaggregant by 21%, and an anticoagulant by 2% (see table)
Results
The follow-up visit included the evaluation of post-covid infection quality-of-life, standard laboratory tests, chest computed tomography, spirometry with evaluation of DLCO. The onset of cardiovascular events during the average period of 384 days was evaluated. None of the 43 patients had major cardiovascular events: coronary heart disease, cerebrovascular disease, peripheral arterial disease, deep vein thrombosis and pulmonary embolism.
Conclusions
Even if this study failed to demonstrate new-onset CV events, longer follow-up studies performed to evaluate cardiovascular risk following SARS-CoV1 infection showed persistent hyperlipidemia, cardiovascular system abnormalities, and glucose metabolism disorders in a very high number of patients. Further analyses are needed to further investigate longer term cardiovascular consequences of SARS-CoV2 infection.
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