111 research outputs found

    Long term remodeling of rat pial microcirculation after transient middle cerebral artery occlusion and reperfusion.

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    Objective: The aim of this study was to assess the in vivo structural and functional remodeling of pial arteriolar networks in the ischemic area of rats submitted to transient middle cerebral artery occlusion (MCAO) and different time intervals of reperfusion. Methods and results: Two closed cranial windows were implanted above the left and right parietal cortex to observe pial microcirculation by fluorescence microscopy. The geometric characteristics of pial arteriolar networks, permeability increase, leukocyte adhesion and capillary density were analyzed after 1 h or 1, 7, 14 or 28 days of reperfusion. MCAO and 1-hour reperfusion caused marked microvascular changes in pial networks. The necrotic core was devoid of vessels, while the penumbra area presented a few arterioles, capillaries and venules with severe neuronal damage. Penumbra microvascular permeability and leukocyte adhesion were pronounced. At 7 days of reperfusion, new pial arterioles were organized in anastomotic vessels, overlapping the ischemic core and in penetrating pial arterioles. Vascular remodeling caused different arteriolar rearrangement up to 28 days of reperfusion and animals gradually regained their motor and sensory functions. Conclusions: Transient MCAO-induced pial-network remodeling is characterized by arteriolar anastomotic arcades. Remodeling mechanisms appear to be accompanied by an increased expression of nitric oxide synthases

    Arrhythmic risk in elderly patients candidates to transcatheter aortic valve replacement. predicative role of repolarization temporal dispersion

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    Degenerative aortic valve stenosis (AS) is associated to ventricular arrhythmias and sudden cardiac death, as well as mental stress in specific patients. In such a context, substrate, autonomic imbalance as well as repolarization dispersion abnormalities play an undoubted role. Aim of the study was to evaluate the increase of premature ventricular contractions (PVC) and complex ventricular arrhythmias during mental stress in elderly patients candidate to the transcatheter aortic valve replacement (TAVR). In eighty-one elderly patients with AS we calculated several short-period RRand QT-derived variables at rest, during controlled breathing and during mild mental stress, the latter being represented by a mini-mental state evaluation (MMSE). All the myocardial repolarization dispersion markers worsened during mental stress (p < 0.05). Furthermore, during MMSE, low frequency component of the RR variability increased significantly both as absolute power (LFRR) and normalized units (LFRRNU) (p < 0.05) as well as the low-high frequency ratio (LFRR/HFRR) (p < 0.05). Eventually, twenty-four (30%) and twelve (15%) patients increased significantly PVC and, respectively, complex ventricular arrhythmias during the MMSE administration. At multivariate logistic regression analysis, the standard deviation of QTend (QTesd), obtained at rest, was predictive of increased PVC (odd ratio: 1.54, 95% CI 1.14–2.08; p = 0.005) and complex ventricular arrhythmias (odd ratio: 2.31, 95% CI 1.40–3.83; p = 0.001) during MMSE. The QTesd showed the widest sensitive-specificity area under the curve for the increase of PVC (AUC: 0.699, 95% CI: 0.576–0.822, p < 0.05) and complex ventricular arrhythmias (AUC: 0.801, 95% CI: 0.648–0.954, p < 0.05). In elderly with AS ventricular arrhythmias worsened during a simple cognitive assessment, this events being a possible further burden on the outcome of TAVR. QTesd might be useful to identify those patients with the highest risk of ventricular arrhythmias. Whether the TAVR could led to a QTesd reduction and, hence, to a reductionof thearrhythmicburdenin thissettingofpatients isworthytobe investigated

    Effect of Foliar Treatments with Calcium and Nitrogen on Oregano Yield

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    Oregano, Origanum vulgare L., is a perennial herbaceous plant belonging to the Lamiaceae family. Oregano shows variations in biomass yield and essential oil (EO) content due to the influence of abiotic and biotic factors. The aim of this study was to assess the effect of different foliar applications based on calcium (Ca) and nitrogen (N) on morphological and productive parameters in oregano. Tests were carried out in Sicily (Italy) in 2020–2021. In each year, eight foliar applications were applied. Only flowers and leaves were used for the extraction of the EO. For all parameters in the study, except for plant height and inflorescence length, the highest values were found in treated plants with respect to the control. In plants treated with calcium and nitrogen, an increase of between 0.6 and 1.6 t ha−1 was observed for fresh yield, and an increase of between 0.5 and 0.9 t ha−1 was observed for dry yield. The increase in biomass yield led to an increase in EO yield of between 4 and 12 kg ha−1. The results highlight that foliar treatments with Ca in combination with N enable growth in crop production in environments that show poor water availability

    How Slight Solidification Rate Variations within Cast Plate Affect Mechanical Response: A Study on As-Cast A356 Alloy with Cu Additions

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    The present work investigates a narrow range of secondary dendrite arm spacing (SDAS), in an as-cast A356 alloy with and without copper (Cu) additions. Cu was added to the base A356 alloy melt to reach the target concentration of 0.5 and 1 wt.%. Samples were selected from 3 different positions within the cast plate, offering 30, 35, and 40 μm SDAS variants. Tensile curves revealed a strong influence between the specimen cutting position and strength, with a pronounced effect in the Cu-containing alloys. Hardness measurements did not confirm the tensile response; hence, to understand the phenomenon, microstructural features have been investigated in detail. Eutectic silicon (Si) particle equivalent diameter (ED) size decreased from the top (T) to the bottom (B) position of the cast. Eutectic Si particle surface area (A%) was found to be denser at the B as compared to the T and simultaneously in the Cu-containing alloy as compared to the Cu-free reference alloy. Backscattered electron (BSE) images were employed to investigate the nature of the Cu-rich intermetallic phases. In conclusion, electrical conductivity measurements were performed to confirm the trends observed

    Effects of irrigation, peat-alternative substrate and plant Habitus on the morphological and production characteristics of Sicilian rosemary (Rosmarinus officinalis L.) biotypes grown in pot

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    Irrigation and growing substrate are considered as essential cultivation practices in order to obtain good productive and qualitative performance of potted rosemary plants. In pot growing, the chemical, physical and biological characteristics of the substrate must be stable over time in order to allow regular plant growth. However, the effects of cultivation techniques on the characteristics of potted rosemary are little known. Peat is traditionally used as the organic growing medium; however, despite numerous advantages, its use has determined a degradation of peatlands in the northern hemisphere and an increase in greenhouse gases in the atmosphere. The aim of the present study was to assess the effects of irrigation and peat-alternative substrates on the morphological, aesthetic and production characteristics of potted Sicilian rosemary biotypes with different habitus types. Two years, two different irrigation levels, three peat-alternative substrates and three types of rosemary plant habitus were tested in a split-split-split-plot design for a four-factor experiment. The results highlight that irrigation and substrate determined significant differences for all tested parameters. Rosemary plants demonstrated the best performances when irrigation was more frequent; vice versa, the greatest percent content in essential oil was obtained when irrigation events were less frequent. The chemical–physical characteristics of peat-alternative substrates changed with decreases in the peat content and increases in the compost content. The erect habitus biotype showed the best adaptation capacity to the various treatments. Our results suggest that irrigation and peat-alternative substrates significantly affect the growth of rosemary plants and should, therefore, be taken into consideration in order to improve the cultivation of this species in pots for ornamental purposes

    Palmitoylethanolamide reduces granuloma-induced hyperalgesia by modulation of mast cell activation in rats

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    The aim of this study was to obtain evidences of a possible analgesic role for palmitoylethanolamide (PEA) in chronic granulomatous inflammation sustained by mast cell (MC) activation in rats at 96 hours. PEA (200-400-800 μg/mL), locally administered at time 0, reduced in a concentration-dependent manner the expression and release of NGF in comparison with saline-treated controls. PEA prevented nerve formation and sprouting, as shown by histological analysis, reduced mechanical allodynia, evaluated by Von Frey filaments, and inhibited dorsal root ganglia activation. These results were supported by the evidence that MCs in granuloma were mainly degranulated and closely localized near nerve fibres and PEA significantly reduced MC degranulation and nerves fibre formation. These findings are the first evidence that PEA, by the modulation of MC activation, controls pain perception in an animal model of chronic inflammation, suggesting its potential use for the treatment of all those painful conditions in which MC activation is an initial key step

    Malvidin's Effects on Rat Pial Microvascular Permeability Changes Due to Hypoperfusion and Reperfusion Injury

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    The present study was aimed to evaluate the malvidin's protective effects on damage induced by 30 min bilateral common carotid artery occlusion (BCCAO) and 60 min reperfusion (RE) in rat pial microcirculation. Rat pial microcirculation was observed using fluorescence microscopy through a closed cranial window. Western blotting analysis was performed to investigate the endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (p-eNOS) and matrix metalloproteinase 9 (MMP-9) expression. Moreover, MMP-9 activity was evaluated by zymography. Finally, neuronal damage and radical oxygen species (ROS) formation were assessed. In all animals, pial arterioles were classified in five orders of branching according to Strahler's method. In hypoperfused rats, 30 min BCCAO and 60 min RE caused a decrease in arteriolar diameter, an increase in microvascular leakage and leukocyte adhesion, accompanied by decreased capillary perfusion and red blood cell velocity (VRBC). Moreover, marked neuronal damage and evident ROS generation were detected. Conversely, malvidin administration induced arteriolar dilation in dose-related manner, reducing microvascular leakage as well as leukocyte adhesion. Capillary perfusion and VRBC were protected. Nitric oxide (NO) synthase inhibition significantly attenuated malvidin's effects on arteriolar diameter. Western blotting analysis revealed an increase in eNOS and p-eNOS expression, while zymography indicated a decrease in MMP-9 activity after malvidin's administration. Furthermore, malvidin was able to prevent neuronal damage and to decrease ROS generation. In conclusion, malvidin protects rat pial microcirculation against BCCAO/RE injury, preventing blood-brain impairment and neuronal loss. Malvidin's effects appear to be mediated by eNOS activation and scavenger activity

    SARS-CoV-2 vaccination and multiple sclerosis: a large multicentric study on relapse risk after the third booster dose

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    Background: COVID-19 vaccines have been recommended to people with multiple sclerosis (pwMS) and, to ensure durable immunity, a third booster dose has been administered in several countries. Data about potential risks associated with the third booster dose in pwMS, such as vaccine-triggered disease exacerbations, are still scarce. Objective: To investigate whether the administration of a third booster dose of mRNA COVID-19 vaccines was associated with an increased risk of short-term disease reactivation in a large cohort of pwMS. Methods: We retrospectively selected 1265 pwMS who received a third booster dose of an mRNA COVID-19 vaccine. Demographic and clinical data were collected, including the presence, number and characteristics of relapses in the 60 days prior to and after the third booster dose. Results: In the selected cohort, the relapse rate in the two months after administration of the third booster dose of mRNA COVID-19 vaccines did not increase when compared with the prior two months. Indeed, the percentage of pwMS experiencing relapses in the 60 days following the administration of the third booster dose was 2.1%, similar to the percentage recorded in 60 days prior to vaccination, which was 1.9%. Conclusions: The third booster dose of mRNA COVID-19 vaccines appeared to be safe for pwMS
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