Authors:A. Pálffy, Márta Janáky, I. Fejes, Gy Horváth and Gy Benedek
To compare the interocular amplitude differences of the multifocal electroretinograms (mfERGs) evoked by either monocular or binocular stimulation in healthy subjects with good vision.
Thirty-five subjects were included in the study. A Roland Consult RETIscan system was used. DTL electrodes were employed. First, the right and left eyes were stimulated separately, then, binocular stimulation was applied. The amplitudes of the scalar products were averaged over five concentric retinal regions (rings).
The interocular amplitude differences were 21.55% (SD: ±12.72) under monocular conditions and 18.69% (SD: ±11.64) under binocular conditions. No significant differences were found between the amplitudes and variability values obtained under either monocular or binocular stimulation.
Our results provided no evidence for the advantage of either binocular or monocular stimulating conditions in obtaining mfERGs. A considerable side difference was found between the mfERGs of the two eyes in almost all individual cases.
Authors:Gy Kovács, Z. Petrovszki, J. Mallareddy, G. Tóth, Gy Benedek and Gyöngyi Horváth
This study reports on the in vivo effects of four endomorphin-2 (EM-2) derivatives (EMD1-4) containing unnatural amino acids, i.e. 2-aminocyclohexanecarboxylic acid (Achc2), para-fluorophenylalanine (pFPhe4), β-methylphenylalanine (βMePhe4) and/or 2′,6′-dimethyltyrosine (Dmt1). After induction of osteoarthritis by monosodium iodoacetate into the ankle joint of male Wistar rats, a chronic intrathecal catheter was inserted for spinal drug delivery. The mechanical threshold was assessed by a dynamic aesthesiometer. Intrathecal injection of the original EM-2 and the ligands (0.3–10 μg) caused dose-dependent antiallodynic effects. The comparison of the different substances revealed that EMD3 and EMD4 showed more prolonged antinociception than EM-2, and the effects of the highest dose of EMD4 were comparable to morphine, while EMD3 caused paralysis at this dose. The potency of the different ligands did not differ from EM-2. The results show that the derivatives of EM-2 have similar in vivo potency to the original ligand, but their effects were more prolonged suggesting that these structural modifications may play a role in the development of novel endomorphin analogues with increased therapeutic potential.