[The Effect of the Disease Duration on the Changes of the Visual Evoked Potentials and Contrast Sensitivity in Multiple Sclerosis].

The most sensitive methods to detect pathological changes in the visual system are the method of recording visual evoked potentials and the psychophysical method of measuring contrast sensitivity. Described in the literature features of functional disorders of the visual system in patients with multiple sclerosis are controversial. The results of the study allowed us to make an assumption about the depen-dence of the nature and severity of changes of the evoked potentials and contrast sensitivity and the duration of disease in patients with multiple sclerosis.

The human magno and parvo systems and selective impairments of their functions.

The magno and parvo systems, consisting of large and small cells respectively and showing the greatest differences in temporospatial characteristics, are two of the most interesting channels in the organization of retinotopic input pathways of the human visual system. We tested the hypothesis that selective lesions of fibers of a specified diameter occurring in pathology of the conducting pathways, i.e.

[Human magno- and parvo-systems and selective disruptions in their function].

In psychophysical and electrophysiological investigations, we tested the hypothesis that in patients with multiple sclerosis at its early stage either phasic cells of the magnocellular pathway or tonic cells of the parvocellular pathway are disturbed. Healthy humans and patients with early stage of diseases have a contrast spatial-frequency sensitivity measure. The decrease in sensitivity at low, medium and high spatial frequency indicates changes in parvo- and magno-system activity.

[Visual evoked potentials in response to dichoptic presentation of sinusoidal grating and noise background].

Dichoptic stimulation was used in comparison of visual evoked potentials (VEPs) with those obtained with monocular stimulation (recordings made from the occipital area). 16 subjects viewed sinusoidal gratings with the right eye while a visual noise was added via a mirror for the left eye. In presence of the noise, amplitude of the early VEP components' N1, P1b, and the late component P2 decreased, P1a is not changed in presence of the noise, and the late negative wave N2 increased for all spatial frequencies.

[Individualization of the amikacin administration regimen on the basis of the relationship between its pharmacokinetics and the patient's status].

Dosage individualization based on quantitative relationships between pharmacokinetic parameters and anatomophysiological and/or pathological factors, patient's factors (PFs) is of importance in designing optimal regimens. Unfortunately, the attempts to correlate aminoglycoside pharmacokinetic parameters and PFs often failed perhaps due to insufficient numbers of PFs under investigation. That is why we sought to involve more PFs, especially nontraditional ones, for explaining intersubject variability of the amikacin model-independent parameter in 20 patients with purulent inflammatory processes.