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Biomedical subjects

E Kammerer

Publications and source records attributed to E Kammerer.

At least 19 recordsLinked to original sources
PubMed1988

[Prevalence and diagnostic value of so-called neurologic soft signs in a larger sample of severely hearing impaired 10 to 13-year-old children].

262 severely hard-off hearing and deaf 10-13 years old children were screened by a short, standardised neurological examination consisting of 7 items. The results showed a high rate of socalled soft signs especially in form of associated movements. It seemed remarkable that the rate of soft signs did not diminish over the age range examined. Statistical relations of these results to other variables of the whole study (gross motor coordination, hyperkinetic behaviour, global psychiatric ratings) support the hypothesis that soft signs are predictors of psychiatric morbidity in general.

Brain↗
PubMed1986

Suppressive effect of cyclosporin A on the development of Leishmania tropica-induced lesions in genetically susceptible BALB/c mice.

The effect of cyclosporin A (CyA) application on the development of cutaneous lesions was analyzed in genetically susceptible BALB/c mice infected s.c. with Leishmania tropica promastigotes. Daily i.p. injections of CyA, beginning 2 days before or at the day of the infection, dose dependently inhibited the development of parasite-induced lesions; no effect on the lesions was observed, however, if CyA application was started 14 days after the infection. Cessation of CyA administration after having successfully suppressed the cutaneous lesions for a period of 42 days, resulted in the development of lesions within 3 days. CyA had no inhibitory effect on lesions developing in L. tropica infected hypothymic BALB/c nu/nu mice. CyA or CyA-containing mouse serum did not directly affect the viability and the growth rate of L. tropica promastigotes, suggesting that the effect of the agent was imposed on the cells participating in the formation of the cutaneous lesions. Quantitative analysis of the cell distribution in the spleens of infected mice revealed that CyA markedly suppressed the infection-associated numerical increase of splenocytes. Within the Thy-1+ lymphocyte compartment, CyA had its most pronounced effect on the Lyt-1+ T lymphocyte subset. Early in the disease, the frequency of splenic cells proliferating in response to L. tropica antigen in vitro was clearly inhibited by CyA; in the later stages of the infection, however, this effect could not be observed, indicating the presence of L. tropica-inducible T cells being relatively resistant to CyA. Taken together, our findings indicate that CyA reversibly inhibits or delays the parasite-induced expansion of Lyt-1+ splenic T lymphocytes, and thus suppresses the biological function of those T cells that are instrumental for the formation of cutaneous lesions in L. tropica-infected BALB/c mice.

Animals↗
PubMed1985

Action of (D-Pro4)-beta-casomorphin1-5 on processes of synaptic transmission.

The peptide (D-Pro4)-beta-casomorphin1-5 is a potent and long acting analgesic. Furthermore it is able to antagonize apomorphine-induced behavioral patterns, which are preferentially used as screening methods to detect dopaminolytic or neuroleptic properties. Because all of these tests do not exclude interaction of drugs with transmission systems other than the dopaminergic, biochemical studies were undertaken to estimate possible influences of the opioid peptide on processes of dopaminergic, serotonergic, and cholinergic transmission systems. In lower concentrations (D-Pro4)-beta-casomorphin1-5 enhances the potassium-stimulated release of acetylcholine from hippocampal slices and the basal overflow of dopamine from striatal slices. In high concentrations an augmentation of the potassium evoked release of dopamine and a reduction of the binding of [3H]spiperone on dopaminergic and serotonergic striatal receptors could be observed. These biochemical findings are discussed with regard to the behavioral patterns induced by this opioid peptide.

Acetylcholine↗
PubMed1985

The influence of enhanced K+-concentration on the uptake and acetylation of choline in hippocampus slices of rats.

The effect of K+-evoked acetylcholine (ACh) release on uptake and acetylation of choline (Ch) in hippocampus slices of rats was studied by use of two different temporal schedules of incubation with labeled precursor and K+-stimulation of tissue. When the incubation with labeled Ch was performed before K+-stimulation, a significant increase of ACh release up to about 400% could be observed. From hippocampus tissue Ch and ACh were extracted as free, labile bound and stable bound fractions. Immediately after the end of potassium stimulation only the ACh radioactivity of the labile bound fraction was decreased, whereas the Ch radioactivities were not changed. In a second series of experiments the K+-evoked ACh release was finished immediately, 10 or 25 min before incubation with labeled precursor. At this time the ACh radioactivity in the incubation medium was normalized. On the other hand, the Ch and ACh radioactivities in the hippocampus tissue increased and returned to control values by different time courses. 30 min after potassium stimulation the ACh radioactivities were still increased, whereas the Ch radioactivities were already normalized to control level. The calculation of the totals of released ACh radioactivity and Ch and ACh radioactivities of tissue suggests that the potassium evoked release leads to a higher uptake and acetylation irrespective of whether the stimulation was carried out before or after the incubation with labeled precursor.

Acetylcholine↗
PubMed1981

[The effect of conditioning on the ultrastructural distribution of synaptic vesicles in the hippocampus of the rat].

In three months old male Wistar-rats the influence of conditioning (brightness discrimination reaction) on the number and distribution of vesicles of the synapses in the stratum radiatum (CA 3) of the hippocampus were investigated. A total of 15 rats (5 trained rats, 5 passive and 5 active controls) were studied by the aid of electron microscopic and morphometric methods. The number of synaptic vesicles was evaluated for the passive controls by 27 vesicles per synaptic area. In the CA 3-region 70 minutes after training the calculation of the number of synaptic vesicles revealed a significant decrease in comparison with passive and active controls (16 and 32 vesicles per synaptic area, respectively; significant difference at p less than 0.05). The volume of the synaptic vesicles was reduced for the trained rats by 20-25% in comparison with controls. The morphological results after training could be correlated with the changes of the Ach fractions, and seem to be of great significance at the initial stages of memory formation.

Acetylcholine↗
PubMed1980

Choline uptake and permanent memory storage.

The uptake of 3H-choline and its incorporation into 3H-acetylcholine was studied in vitro on hippocampus slices obtained from animals showing a good or poor long-term memory. The animals were selected on the basis of their retention performance when tested by a brightness discrimination model. The 3H-choline uptake and the incorporation of 3H-choline into 3H-acetylcholine was higher in hippocampus slices from animals showing good retention compared to those from animals with poor retention. The level of high affinity uptake of choline into hippocampus slices may serve as an indicator of the cholinergic activity in this structure under in vitro conditions. The present findings suggest that individual differences in the activity level of the hippocampal cholinergic system do exist and are capable of influencing the retention of the individual animals to a variable degree.

Acetylcholine↗
PubMed1980

Electron microscopic and morphometric studies on synaptic plasticity in the hippocampus of the rat following conditioning.

1. In 40 three months old Wistar rats (16 trained animals, 14 active controls, 10 passive controls) the influence of learning (brightness discrimination) on the number of electronmicroscopically detectable synapses per area neuropil was studied in the stratum radiatum (CA 1) of the hippocampus. 2. 70 minutes after completion of training, the mean number of synapses has significantly increased as compared to active controls (trained animals 14.26 +/- 2.95 synapses/25 micrometer2; active controls 10.23 +/- 2.80 synapses/25 micrometer2; p less than 0.001). 3. 24 hours after training this increase in trained animals still persisted (trained animals 14.15 +/- 2.60, active controls 11.39 +/- 2.87 synapses/25 micrometer2; p less tha 0.001). 4. 14 days after training, the number of synapses has decreased considerably, but was nevertheless significantly higher than in the active controls (trained animals 12.49 +/- 2.76, active controls 11.45 +/- 3.10; p less than 0.001). 5. The results are discussed with regard to their significance to the different stages of memory formation in the CNS.

Animals↗