ABSTRACT
To compare corneal endothelial cell features after cataract surgery performed using fixed torsional or conventional [Pulse] ultrasound mode. In this randomized comparative study, 60 eyes were randomly and equally divided into two groups of torsional or longitudinal mode phacoemulsification. All surgeries were performed by an experienced surgeon, and the outcomes were evaluated by a masked examiner. Preoperatively visual acuity [VA], age and mean nuclear grade [LOCS III] were recorded; besides automated confocal microscopy was used to measure ECD, polymegathism and pleomorphism at the centre of the cornea. All patients underwent clear cornea phacoemulsification in a similar manner. Intraoperative outcome measures were ultrasound time [UST], cumulative dissipated energy [CDE], and total fluid use. Best corrected VA and confocal measurements were repeated after 1 month. Mean preoperative ECD in conventional and torsional phaco mode groups were 2761.61 +/- 403.36 and 2690.36 +/- 490.92 cells/mm2. Postoperative ECD was 2494.30 +/- 358.63 and 2436.56 +/- 468.39 cells/mm2, respectively. The decrease in ECD, and increase in pleomorphism and polymegatism were statistically significant within both study groups [P<.001], but there were no statistically significant differences in preoperative and postoperative measurements between the 2 groups [P>.01]. No relevant clinical differences or operative complications were seen in either group. There were no statistically significant difference between intraoperative measures in both groups [P>.01]. Both phaco methods provide effective lens removal with no significant difference
ABSTRACT
Background and Purpose: Application of low-frequency stimulation [LFS] induces anticonvulsant effects. In this study, the effect of changes in LFS frequencies on its anticonvulsant effects in kindling model of epilepsy was investigated by determining the behavioral and ultrastructural changes
Methods and Materials: In this experimental study, 45 Wistar rats weighing 250-280 g were used. For induction of kindled seizures, stimulating and recording electrodes were implanted in perforant path and dentate gyrus respectively. Animals were stimulated in a rapid kindling manner. Different groups of animals received LFS at different frequencies [0.5, 1 and 5 Hz] following kindling stimulations and their effects on kindling rate were determined using behavioral and electrophysiological studies
After stimulating the animals for 7 days, they were killed and their dentate gyri were sampled for ultrastructural studies under electron microscopy. For data analysis, one-way and two-way ANOVA, LSD, Kruskal Wallis and Mann Whitney U were used in Statistica 2
Results: Different LFS frequencies had a significant inhibitory effect on kindling rate and decreased after-discharge duration and the number of stimulations to achieve stage 4 and 5 seizures significantly. In addition, application of LFS prevented the increase in the post-synaptic density and induction of concave synaptic vesicles following kindling. There was not any significant change between anticonvulsant effects of LFS at different frequencies
Conclusion: Obtained results show that LFS application can prevent the neuronal hyper-excitability by preventing the ultrastructural changes during kindling, and can exert its anticonvulsant effects
ABSTRACT
It has been suggested that low frequency stimulation [LFS] exerts its inhibitory effect on epileptogenesis through adenosine receptors activation. In the present study, effect of different LFS frequencies on A1 and A2A receptors gene expression was investigated in perforant path kindled seizures. Animals were kindled by perforant path stimulation. Afterdischarges were recorded from the dentate gyrus. LFS [0.5, 1 and 5 Hz] was applied at the end of each kindling stimulation. On the 7th day, A1 and A2A receptors gene expression were evaluated in the dentate gyrus. Application of different LFS frequencies retarded the kindling acquisition. Also, it decreased the afterdischarge durations and behavioural seizure stages 4 and 5 significantly. LFS application prevented the kindling induced decrease in the A1 receptor gene expression. On the other hand, LFS attenuated the level of A2A receptor gene expression in the dentate gyrus. LFS had the most effect at the frequency of 5 Hz. It may be suggested that antiepileptogenic effects of LFS is mediated somehow through changes in the gene expression of adenosine A1 [which has inhibitory effects] and A2A [which has excitatory effects] receptors. These effects might be somehow frequency dependent