Afterimage movement during saccades in the dark.

The spatial values of retinal coordinates are "recalibrated" to the "egocentric" coordinates during and after a saccade within a fraction of a second. We measured the time constant of this retinal coordinate transformation by means of an afterimage technique: our ten subjects performed "auditory" horizontal saccades in total darkness (0.2-4.5 saccades/sec). At a saccade frequency below 1 saccade/sec, the subjects observed saccadic displacement of the foveal afterimage, but the afterimage seemed to arrive at its final position more slowly than the center of gaze (state 1). At saccade frequencies above 1.5 saccades/sec, the perceived amplitude of afterimage displacement decreased with increased saccade frequency (state 2). Above 2 saccades/sec all subjects perceived two stationary afterimages simultaneously at the saccadic end-position (state 3). A further increase in saccade frequency reduced the distance between the two afterimages till only one stationary afterimage was seen in a mid-position between the two auditory targets at a saccade frequency above 3.2-3.5 saccades/sec (state 4). Saccade amplitude remained constant within the frequency range between 0.2 and 4.5 saccades/sec. A one-step or two-step linear model was applied to simulate the experimental data, indicating that the spatial coordinates shift more slowly than the saccadic eye movements.

[Andrological, biochemical and endocrinological studies of subfertile men during kallikrein therapy]. / Andrologische, biochemische und endokrinologische Untersuchungen bei subfertilen Männern während Kallikreintherapie.

31 men with idiopathic oligozoospermia and 23 men with idiopathic asthenozoospermia were treated three months by oral administration of daily 600 units kallikrein. In a greater number of patients apart from the semen analysis different seminal plasma proteins and enzymes as well as hormones in serum (LH, FSH, prolactin, testosterone) and in seminal plasma (LH, prolactin) were determined. There was a significant increase of sperm count and sperm motility in the oligozoospermic group. In asthenozoospermic patients sperm motility was significantly increased, however, sperm count decreased within the normal range. Conception rate was 25% in the oligozoospermic goup and 36% in the asthenozoospermic group. A treatment period of three months showed better results than seven weeks and a dosage of 600 units kallikrein daily was significantly better than daily 300 units. During kallikrein therapy mean concentrations of alpha U,x-antichymotrypsin in seminal plasma and serum LH, prolactin and testosterone increased significantly. Seminal plasma levels of LH and prolactin remained unchanged. The mode of action of systemic kallikrein therapy may be at the level of tissue hormones (kinin liberation), however, an increase of the intratesticular testosterone level and an interference with the blood-seminal plasma barrier has also to be considered.

Determination of various semen parameters and sex hormone levels in subfertile men during kallikrein therapy.

Thirty-one (31) subfertile men with idiopathic iligozoospermia were treated by a daily oral medication of 600 units of pancreatic kallikrein (Padutin(R) 100) over a period of 3 months. Total sperm output increased significantly with a maximum 3 months after initiation of therapy. In addition, quantitative and qualitative sperm motility improved during treatment and was still improved 2 months after withdrawal of therapy. Compared to other regimens, oral administration of 600 units kallikrein for a period of 3 months yielded better results than shorter medication periods or lower dosage. Quantitative determination of several serum proteins occurring in seminal plasma before, during and after kallikrein therapy showed a significant increase of alpha 1, x-antichymotrypsin. Thus, kallikrein treatment seems to affect, to a certain degree, the secretory activity of the accessory glands or the blood-seminal plasma barrier. Determination of serum gonadotropins and serum testosterone levels showed a significant increase of LH and testosterone during kallikrein treatment, whereas FSH was unaffected. Thus, systemic kallikrein administration induces significant changes of the pituitary-gonadal axis influencing spermatogenesis and epididymal sperm maturation. However, the local action of kinins as pharmacological active tissue hormones has to be considered too.