Neuroprotective effects of amantadine for experimental acute carbon monoxide poisoning.

OBJECTIVE: Amantadine is known to have a neuroprotective effect in many neurological diseases. This study aims at investigating the neuroprotective effect of amantadine in rats exposed to carbon monoxide (CO) poisoning. MATERIALS AND METHODS: Rats were maintained under standard experimental laboratory conditions and randomized into 4 different groups of 7 each namely control, amantadine only, CO exposure, and amantadine + CO exposure. For immunohistochemical analysis, tissues taken from the prefrontal and hippocampal regions were taken into formalin and kept for at least one day. Afterward, the tissue was followed and blocked for paraffin blocking. N-Methyl D-Aspartate (NMDA) levels in homogenates were studied by the Enzyme-Linked Immunosorbent Assay (ELISA) method. Superoxide dismutase (SOD) and catalase (CAT) activities in the supernatants were studied with commercial kits. Nitric oxide (NO) and Asymmetric Dimethyl Arginine (ADMA) levels were studied by the ELISA method. Enzyme activity values were calculated by dividing the protein values in the supernatants and normalizing them. RESULTS: CAT, SOD, NMDA, ADMA, and NO levels were statistically significantly different between the groups (p < 0.05). According to post-hoc pairwise comparison test results, the values of the control and amantadine groups for CAT, SOD, NMDA, ADMA, and NO parameters were significantly higher than that of CO group. Similarly, values in the control and amantadine groups were considerably higher than values for the amantadine + CO group. NMDA values were significantly lower in group amantadine + CO than in CO group (p: 0.049). CONCLUSIONS: Apoptosis and endothelial damage after CO poisoning is a complex process, and amantadine administration has a limited contribution in preventing this process.

Evolution of vibrational modes of SiO2 during the formation of Ge and Si nanocrystals by ion implantation and magnetron sputtering.

Structural variations of SiOx matrix have been studied with Fourier Transform Infrared Spectroscopy (FTIR) during the formation of Si and Ge nanocrystal. Two frequently used methods, magnetron sputtering and ion implantation have been employed to form SiOx matrix containing excess Si and Ge. The Si-O-Si stretching mode has been deconvoluted to monitor the evolution of SiOx films during the annealing process. The integrated area and the shift in the SiOx peak positions are found to be well correlated with the change of the film stoichiometry and nanocrystal formation. It is shown that the nonstoichiometric SiOx matrix turns into stoichiometric SiO2 as the excess Si and Ge atoms precipitate to form nanocrystals. This process takes place at much lower temperatures for Ge than Si for both ion implantation and magnetron sputtering. FTIR technique is shown to be useful to study the matrix hosting nanocrystals to monitor nanocrystal formation.