136 research outputs found
Effects of magnesium treatment in a model of internal capsule lesion in spontaneously hypertensive rats
<p><b>Background and Purpose:</b> The study aim was to assess the effects of magnesium sulfate (MgSO4) administration on white matter damage in vivo in spontaneously hypertensive rats.</p>
<p><b>Methods:</b> The left internal capsule was lesioned by a local injection of endothelin-1 (ET-1; 200 pmol) in adult spontaneously hypertensive rats. MgSO4 was administered (300 mg/kg SC) 30 minutes before injection of ET-1, plus 200 mg/kg every hour thereafter for 4 hours. Infarct size was measured by T2-weighted magnetic resonance imaging (day 2) and histology (day 11), and functional recovery was assessed on days 3 and 10 by the cylinder and walking-ladder tests.</p>
<p><b>Results:</b> ET-1 application induced a small, localized lesion within the internal capsule. Despite reducing blood pressure, MgSO4 did not significantly influence infarct volume (by magnetic resonance imaging: median, 2.1 mm3; interquartile range, 1.3 to 3.8, vs 1.6 mm3 and 1.2 to 2.1, for the vehicle-treated group; by histology: 0.3 mm3 and 0.2 to 0.9 vs 0.3 mm3 and 0.2 to 0.5, respectively). Significant forelimb and hindlimb motor deficits were evident in the vehicle-treated group as late as day 10. These impairments were significantly ameliorated by MgSO4 in both cylinder (left forelimb use, P<0.01 and both-forelimb use, P<0.03 vs vehicle) and walking-ladder (right hindlimb score, P<0.02 vs vehicle) tests.</p>
<p><b>Conclusions:</b> ET-1–induced internal capsule ischemia in spontaneously hypertensive rats represents a good model of lacunar infarct with small lesion size, minimal adverse effects, and a measurable motor deficit. Despite inducing mild hypotension, MgSO4 did not significantly influence infarct size but reduced motor deficits, supporting its potential utility for the treatment of lacunar infarct.</p>
Comparative study of inhibitory efficacy of methionine and its derivatives in acidic medium by mild steel
Corrosion inhibition effect of L-Methionine (MT1), L-Methionine sulfoxide (MT2) and L-Methionine sulfone (MT3) on mild steel corrosion in 1M HCl solution was studied by using weight loss, electrochemical polarization and electrochemical impedance spectroscopy (EIS) techniques. The experimental results showed that the inhibitory efficiency of the three aminoacids improves with the increase of concentration to reach the maximum value of 95.20% for MT1, 94.14% for MT2 and 88.92% for MT3 for a concentration of 10-3M, which translates that the surface covered by the inhibitor increases with the concentration. The effect of temperature on the corrosion rate was investigated and some thermodynamic parameters were calculated. Polarization studies show that three studied inhibitors suggested that three inhibitors control the anodic as well as cathodic reactions and act as mixed type in nature. The results show that MT1, MT2 and MT3 are good inhibitors, and the adsorption of each inhibitor on mild steel surface obeys Flory-Huggins and Langmuir, with a better fit of the Langmuir isotherm through mixed adsorption (physisorption as well as chemisorption) process. In addition, the quantum approach based on density functional theory (DFT), monte Carlo (MC) and molecular dynamics (MD) simulations was confirmed the reactivity of the studied compound towards the corrosion process
The Influence of Some Pyrazole Derivatives on The Corrosion Behaviour of Mild Steel in 1M HCl Solution
Abstract The inhibitive action of some pyrazole derivatives, namely N1, N1-bis (2-(bis ((3,5-dimethyl-1H-pyrazol-1-yl) methyl) amino)ethyl)-N2, N2-bis ((3,5-dimethyl-1H-pyrazol-1-yl) methyl) ethane-1,2-diamine: PAP and diethyl 1,1'-(((4-acetylphenyl) azanediyl) bis (methylene)) bis (5-methyl-1H-pyrazole-3-carboxylate): PAC against the corrosion of mild steel in 1 M HCl solution has been investigated using weight loss measurements, Tafel polarisation and electrochemical impedance spectroscopy (EIS) techniques. The experimental results obtained revealed that these compounds inhibited the steel corrosion in acid solution, the protection efficiency increased with increasing inhibitors concentration. The results obtained from the different corrosion evaluation techniques are in good agreement. Potentiodynamic polarisation studies clearly showed that PAP and PAC acted as mixed inhibitors affecting both cathodic and anodic corrosion currents. Adsorption of these inhibitors on steel surface obeyed to Langmuir adsorption isotherm. Thermodynamic data of adsorption showed that inhibition of steel corrosion in 1M HCl solution by pyrazole compounds is due to the formation of a chemisorbed film on the steel surface. SEM and EDX supported the adsorption conclusions
Consolidation of an Olfactory Memory Trace in the Olfactory Bulb Is Required for Learning-Induced Survival of Adult-Born Neurons and Long-Term Memory
Background: It has recently been proposed that adult-born neurons in the olfactory bulb, whose survival is modulated by learning, support long-term olfactory memory. However, the mechanism used to select which adult-born neurons following learning will participate in the long-term retention of olfactory information is unknown. We addressed this question by investigating the effect of bulbar consolidation of olfactory learning on memory and neurogenesis. Methodology/Principal Findings: Initially, we used a behavioral ecological approach using adult mice to assess the impact of consolidation on neurogenesis. Using learning paradigms in which consolidation time was varied, we showed that a spaced (across days), but not a massed (within day), learning paradigm increased survival of adult-born neurons and allowed long-term retention of the task. Subsequently, we used a pharmacological approach to block consolidation in the olfactory bulb, consisting in intrabulbar infusion of the protein synthesis inhibitor anisomycin, and found impaired learning and no increase in neurogenesis, while basic olfactory processing and the basal rate of adult-born neuron survival remained unaffected. Taken together these data indicate that survival of adult-born neurons during learning depends on consolidation processes taking place in the olfactory bulb. Conclusion/Significance: We can thus propose a model in which consolidation processes in the olfactory bulb determine both survival of adult-born neurons and long-term olfactory memory. The finding that adult-born neuron survival durin
Increased pro-inflammatory cytokines, glial activation and oxidative stress in the hippocampus after short-term bilateral adrenalectomy
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