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Biomedical subjects

M Windisch

Publications and source records attributed to M Windisch.

At least 55 records · Page 3Linked to original sources
PubMed1998

Early postnatal stimulation influences passive avoidance behaviour of adult rats.

In this study, the effects of stimulation on either postnatal days 1 to 7 or 21 to 27 on the passive avoidance reaction (PAR) of 3-month-old rats were examined. Animals received tactile or visual stimulation or tactile-visual stimulation for 10 min each day, and were trained at the beginning of the 4th month of life in a step-through apparatus using a footshock of 0.5 mA. Memory retention was measured 24, 48, 72, 96, and 120 h after the acquisition trial. Step-through latencies to enter the dark compartment and the total duration of stay in the illuminated compartment were recorded up to 200 s. Rats that received tactile or a combined tactile-visual stimulation during the 1st postnatal week displayed significantly longer PAR latencies and a longer duration of stay in the illuminated compartment compared to unstimulated control animals. Visual stimulation during the postnatal days 1 to 7 and 21 to 27 resulted in a longer duration of stay in the illuminated compartment. This effect, however, was more pronounced when stimulation was applied during the 1st postnatal week. Rats that received tactile stimulation during the 4th postnatal week showed decreased PAR performance for all measured parameters when compared to animals that received stimulation during the 1st postnatal week. Furthermore, combined tactile-visual stimulation during the 4th postnatal week led to a reduced duration of stay in the illuminated compartment when compared to the stimulation during the 1st postnatal week. These findings can be attributed to the higher degree of plasticity and to a heightened sensitivity to various stimuli in the 1st postnatal week. The results suggest that tactile, visual or combined tactile-visual stimulation have a long-lasting effect on the ability of adult rats to cope with stressful tasks.

Aging↗
PubMed1997

Ameliorative influence of a nootropic drug on motor activity of rats after bilateral carotid artery occlusion.

The effects of the peptidergic nootropic drug Cerebrolysin on spatial memory and motor activity were examined in intact and ischemic rats. Ischemic-hypoxic damage was induced by injection of Na-cyanide followed by bilateral occlusion of common carotid arteries. Immediately afterwards Cerebrolysin or saline was administered, either by continuous intraventricular (i.v.) infusion or by daily intraperitoneal (i.p.) injection. Rats were tested for spatial memory and motor activity in the Morris water maze on days 3 and 4 post-surgery. The best dose of the substance for i.p. administration was known from previous studies. Therefore we had to investigate the dose-response-relationship and tolerability of the drug after i.v. administration in intact rats. Infusion (i.v.) of a high dose of Cerebrolysin (0.57 mg/day) decreased motor activity and spatial memory of intact rats (p < 0.01 and p < 0.05, respectively) but low dose of Cerebrolysin was well tolerated in the intact animals. Ischemia led to deterioration of motor activity in control rats (p < 0.01). Cerebrolysin significantly counteracted deleterious motor changes due to ischemia up to the level of intact controls after both i.v. infusion (0.0057 mg/day) and daily i.p. drug administration (100 mg/kg bw and day) indicating an accelerating recovery after ischemia.

Amino Acids↗
PubMed1996

Death of cultured telencephalon neurons induced by glutamate is reduced by the peptide derivative Cerebrolysin.

Glutamate induced neurotoxicity has been proposed to account for the loss of neurons after ischemia as well as in the cause of neurodegenerative diseases. We have studied the effects of exogenous glutamate on survival of neurons from chick embryo telencephalon, precultured with a peptide derivative for 8 days. The peptide derivative Cerebrolysin is a drug produced by standardised enzymatic breakdown consisting of 80% peptides and 20% amino acids. Toxic effects of acute glutamate exposure were prevented by Cerebrolysin in a concentration-dependent manner. 20 and 40 microliters Cerebrolysin produce distinct neuroprotective effects. However, 80 microliters Cerebrolysin/ml nutrition medium more than doubles neuronal viability compared to untreated control cells. These concentration-dependent effects of Cerebrolysin were evident even at the light microscopic level.

Amino Acids↗
PubMed1996

Effects of two protein-free peptide derivatives on passive avoidance behaviour of 24-month-old rats.

Cerebrolysin is an aqueous protein-free solution produced by biotechnological methods, using a standardised enzymatic breakdown of lipid-free pig brain proteins. The present study investigated the behavioural effects of this peptide derivative PD (100 mg/kg b.wt.), a related experimental peptide derivative PD-exp (1 mg/kg b.wt.) and a 0.9% saline control, on passive avoidance reaction (PAR) of 24-month-old male and female rats. Rats were pre-treated chronically for 7 days. Passive avoidance procedure started one day after the last subcutaneous injection with a single PAR-acquisition training session. Animals were trained in a step-through avoidance task using an unavoidable footshock of 1 mA (2 s). PAR-extinction testing showed that PAR latencies were treatment dependent (p < 0.001) due to the fact that PD and PD-exp treated animals displayed better performance. The same was true for all other behavioural elements observed. In this study we were able to demonstrate that s.c. administration of PD and PD-exp changes the capability of old female but not of old male rats to extinguish step-through behaviour. Because there were no differences in postshock latencies between control females and males we propose different sensitivity for the substances used.

Amino Acids↗
PubMed1996

Dose-dependent behavioural effects of two protein-free peptide derivatives on the passive avoidance reaction of rats.

Cerebrolysin is an aqueous protein-free solution produced by biotechnological methods, using a standardised enzymatic breakdown of lipid-free pig brain proteins. The present study investigated the behavioural effects of various doses (0.01; 0.1; 1; 10 and 100 mg/kg b.wt.) of this peptide derivative PD, and the related experimental peptide derivative PD-exp on passive avoidance reaction (PAR) of 2-month-old rats. PD consists of 15% small peptides (< 10 kD) and 85% free amino acids. The peptide composition of PD-exp is identical to that of PD but the overall peptide concentration is five times greater than that of PD. In the presented experiments, rats were treated with only one single injection of PD, PD-exp or saline as a control. Passive avoidance procedure started 24 h after the subcutaneous injection with a single PAR-acquisition training. Animals were trained in a step-through avoidance task using an unavoidable footshock of 0.75 mA (2 s). PAR extinction testing started 24 h later and was recorded on five consecutive days. The results of our experiments demonstrate that already a single injection of PD (100 mg/kg b.wt.), but to a higher extent of PD-exp (1 mg/kg b.wt.) induce an improvement on PA reaction of 2-month-old healthy rats.

Amino Acids↗
PubMed1995

Effects of postnatal stimulation on the passive avoidance behaviour of young rats.

We examined the effects of stimulation on either postnatal days 1-7 or 21-27 on passive avoidance reaction (PAR) of young rats. Animals received tactile or visual stimulation for 10 min each day, and were trained on postnatal day 28 in a step-through apparatus using a footshock of 0.75 mA for 2 s. Retention was tested on five consecutive days beginning on day 29. Memory retention was measured for each rat 24, 48, 72, 96 and 120 h after the acquisition trial. Step-through latencies to enter the dark compartment, time spent in the illuminated compartment and number of crossings of the light beam were recorded up to 200 s. Rats that received tactile or visual stimulation during the 4th postnatal week displayed significantly lower PAR latencies, a shorter stay in the illuminated compartment and a higher number of crossings of the light beam compared to rats treated during the 1st postnatal week. The untreated control group showed a rapid decline of PAR latencies. All experimental groups remained in the illuminated compartment longer and showed PAR latencies well above those of the control group. The differences became more pronounced when visual stimulation in the first postnatal week was used. The number of crossings of the light beam was significantly reduced by the treatment, with the exception of the experimental group stimulated visually in the 4th week. The behavioural changes induced by tactile or visual stimulation have a long-lasting effect in coping with a stressful task.

Animals↗
PubMed1994

Determination of traces of pyrethrins and piperonyl butoxide in biological material by high-performance liquid chromatography.

A liquid chromatographic method for the determination of pyrethrins and of the synergist piperonyl butoxide in human plasma after C18 solid-phase extraction is described. UV detection was found to be sensitive enough to determine concentrations far below the limit of toxicity. With respect to future investigations concerning studies in biological materials, a column-switching system for sample preparation was developed and compared with solid-phase extraction. Both methods show comparable limits of detection, but the column-switching technique has the advantage of fully automating the system.

Chromatography, High Pressure Liquid↗
PubMed1994

Efficacy of the peptidergic nootropic drug cerebrolysin in patients with senile dementia of the Alzheimer type (SDAT).

Cerebrolysin is a peptidergic nootropic drug with a multimodal mechanism of action. It is expected to have a positive influence on neurodegenerative diseases such as senile dementia of the Alzheimer type (SDAT). Experimental studies have shown Cerebrolysin to have a regulatory effect on energy metabolism, a positive influence on behavior through neuromodulation due to its peptide fraction, and most important, a neurotrophic stimulation. In SDAT and related disorders the neurotrophic effect of the drug could play a major role and influence the progress of the illness. A placebo-controlled double-blind trial was designed to examine the efficacy of the drug in SDAT. Confirmatory statistics were used for analysis. 120 subjects with mild to moderate dementia according to the Global Deterioration Scale (GDS) were included in the trial. Their performance on the Mini Mental State Examination (MMSE) was between 15 and 25. The diagnosis was substantiated by the Hachinski Ischemic Score and cranial computed tomography. The inclusion and exclusion criteria were formulated so as to prevent a distortion between the two arms by secondary dementia or other disease. The two arms received either placebo or the drug once a day (30 ml Cerebrolysin in 100 ml physiological saline i.v.) from Monday to Friday for four weeks. Physiological saline (130 ml) was used as placebo. Primary variables used for the statistical analysis were the Clinical Global Impression (CGI), which measures the improvement in symptoms, the SCAG score, and the performance in the trial-making test (ZVT-G). The self-assessment in the Bf-S and the activities of daily living in the NAI were used as secondary variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Postnatal administration of two peptide solutions affects passive avoidance behaviour of young rats.

The effects of two subcutaneously injected peptide solutions CERE (100 mg/kg b. wt.) and E021 (1 mg/kg b. wt.) and of 0.9% saline on passive avoidance reaction (PAR) of young rats were examined. Animals were trained and tested in a step-through avoidance task using a footshock of 0.5 mA or 1 mA. Step-through latencies were observed up to 200 s and from these data the percentage of good learners (latency = 200 s) and bad learners (latency < 200 s) was calculated. Two experimental schedules were performed (n > 6). In Expt. 1 rat pups were chronically treated with the substances within the first 7 days after birth. In Expt. 2 the 7 days of treatment started in the 4th postnatal week. In both experiments PAR acquisition was trained on the 28th day after birth (learning trial), PAR extinction testing started on the 29th day (retention trials). After applying a 0.5-mA footshock, rat pups treated with E021 within the first 7 days of life (Expt. 1) displayed significantly slower PAR extinction when compared to saline- and CERE-treated rats. In the 1 mA groups, significant differences in step-through latencies were measured between 0.9% saline- and E021-pretreated animals on retention day 11 and between saline and CERE on retention days 9 and 13. E021-treated rats of Expt. 2, receiving a footshock intensity of 0.5 mA, showed significant lower step-through latencies when compared to E021-treated rats of Expt. 1. In Expt. 2 no significant differences between treatment groups were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗