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Biomedical subjects

E Winkelmann

Publications and source records attributed to E Winkelmann.

At least 91 records · Page 5Linked to original sources
PubMed1977

[Automatic pictorial analysis of normal and experimentally altered nervous tissue].

1. Structural changes of the dorsal LGN of the albino rat following unilateral enucleation cause its decrease of volume. 2. Using the Quantimet 720 M and Nissl stained preparations we tried to explain the decreased volume by estimation of three parameters: The whole area of the cells, the number of neurons and the size distribution of cells. 3. The whole area and the number of neurons are constant. 4. The size distribution of cells changes significantly and indicates an alteration of the tissue surrounding the cells (development of the neuropil, loss of fibers). 5. The changes of the maxima of size distributions following enucleation suggest a diminution of the area of neuron somata, but are not significant. 6. Using more exact methods of measurements we want to get more detailed results.

Animals↗
PubMed1977

[Chemotherapeutically effective nitro compounds. 3rd communication: nitropyridines, nitroimidazopyridines and related compounds (author's transl)].

New 2-nitropyridines and 3-nitropyridines, and 3-nitroimidazo-[1,2-a]-pyridines and related compounds (together 106) were synthesized and tested for their chemotherapeutic efficacy against trichomonads, amoebas and other organisms, such as Eimeria tenella, bacteria, fungi, helminths. Several 2-nitropyridines revelaed a detectable systemic effect against Entamoeba histolytica (extraintestinal amoebiasis of the golden hamster) and also a weak activity against Trichomonas fetus in the NMRI-mouse. Only a few 3-nitropyridines showed a marked systemic effect against trichomonads. Of the 3-nitroimidazo-[1,2-a]-pyridines, only the electroneutral carboxylic acid amide group exhibited a pronounced activity, exclusively against trichomonads; however, the activity was nullified again by electronegative, electropositive and other electroneutral substituents. As they were not superior in chemotherapeutic respect compared to the known standard preparation (metronidazole), no further tests were carried out with the most effective compounds.

Amebicides↗
PubMed1977

[Spine density of lamina V pyramidal cells in the visual cortex of laboratory rats after lengthy dark exposure].

1. The spine density was investigated at the apical dendrites of lamina-V-pyramidal cells in the visual cortex of rats following dark rearing for 250 days. 2. There are no significant differences in the average spine density between rats reared in darkness and normal conditions. 3. The results are discussed in view of the significant differences found after dark rearing for 50 days. It is assumed that these present results are caused by a delay in spine development in younger animals, which is compensated in the adult stage.

Animals↗
PubMed1977

[Investigations on the basal dendritic tree of lamina-V-pyramidal cells in the visual cortex of rats after destruction of the lateral geniculate body and after dark raising (author's transl)].

The basal dendritic trees of the lamina-V-pyramidal cells of rats were investigated after 1th unilateral destruction of the dorsal lateral geniculate body (Cgld) 2nd dark raising I. Animals with destroyed Cgld. Comparing the data of free dendritic terminations (FDE), branching points (VZP), number of segments (AdD) and length of segments (LdD) no significant differences have been remarked between--controls of the same litter (non-influenced side),--influenced sides of animals of the same litter. A significant difference between the ipsi- and contralateral hemispheres of animals with unilateral geniculate destruction. II. Dark raised animals There were no significant differences between dark raised animals, their controls and between dark raised animals and controls. The causes of postoperative changings have been discussed. Mainly retrograde degeneration effects may be responsible for the ascertained differences.

Animals↗
PubMed1976

[Electron microscopic and light microscopic studies of optical and cortical afferents in the lateral geniculate body, pars dorsalis, of albino rats with special attention to synaptic organization].

1. In the CGLd of the albino rat there are to be found two forms of retinal terminals in electronmicroscopic investigations, they are identical with 2a and 2b terminals described formerly in Golgi-preparations. 2. The small 2b terminals are situated previously in the extraglomerular neuropil, which is identical with the terminal part of P-neuron dendrites. They establish asymmetric GRAYtype I contacts with dendrites and spines of the relay-cell-dendrites. 3. The large 2a terminals form filamentous contacts with the smooth surfaces of the dendrites of the stem-and branching-zones. Synaptic contacts (GRAY I) are established with the grape-like appendages in the branching zone of P-neuron dendrites. 4. In the glomeruli of the CGLd there are three main components, which are the nerve endings of large optic axons, the interneuron dendritic terminals and the relay-cell-dendrites. They are surrounded by astrocytic processes. 5. In the extra-glomerular neuropil there are numerous small nerve endings, they form GRAY type I contacts with relay-cell-dendrites and their spines. They are partly identical with the type I endings in Golgi-preparations (cortical terminals). 6. After the eye enucleation and ablation of the visual cortex the type 2a and 2b and type 1 terminals degenerate. There are two forms of degeneration, the light and the dark one. 7. After eye enucleation two forms of degenerations in the degenerating retinal axons occur, which are the "watery" and the "dense" form. Besides the astrocytes the oligodendrocytes remove the destroyed particles. 8. The ultrastructural characteristics of the interneuronal dendritic terminals and their possible funktion are discussed. 9. There is added a table of the synonyma of CGLd structures.

Animals↗
PubMed1976

[Studies on the spine density in lamina V pyramidal cells of the visual cortex in young and subadult rats after dark-rearing and destruction of the dorsal nucleus in the lateral geniculate body].

1. Dark reared 50 days old rats have a significantly diminuished number of spines at the apical dendrite of the lamina-V-pyramidal cells in the visual cortex. 2. Likewise we could ascertain a significant diminution of spines after destroying the upsilateral Cgld. The topistical distribution of spine density differs in both investigated series. 3. The spine diminution at the apical dendrites of lamina-V-pyramidal cells differs in this way: pyramidal cells with thick apical dendrites show a weaker spine diminution than the pyramidal cells with thin apical dendrites. 4. Some topistical problems concerning specific afferents in the visual cortex are discussed.

Age Factors↗
PubMed1976

[Chemotherapeutically active nitro compounds. 2nd communication: Nitrodiphenyl sulfones (author's transl)].

A number of new 4-nitro-4'-amino-diphenyl sulfones and related compounds were prepared and investigated as to their therapeutic activity. They showed a good systemic activity against tubercle bacilli (M. bovis, NMRI mouse) and plasmodia (P. berghei, NMRI mouse). The test results reveal that the 4-nitro-4'-amino-diphenyl sulfones possess a spectrum of activity similar to that of diamino-diphenyl sulfone (DDS). It is assumed that 4-nitro-4'-amino-diphenyl sulfones in vivo are converted into DDS derivatives by reduction. The advantages of the new compounds, however, were too insignificant as compared to DDS to justify further extensive trials.

Animals↗
PubMed1976

[Morpho-histochemical investigations about the connection of the mesencephalic reticular formation (Area cuneiformis) to the subcortical structures of the visual system (author's transl)].

There was investigated the connection of the mesencephalic reticular formation (Area cuneiformis) with subcortical structures of the visual system. After coagulation of the reticular formation we studied the connections by degeneration and enzymhistochemistric methods. Terminal degeneration in different intensity was observed in the ventral part of the lateral geniculate in the nucleus lateralis posterior, the pretectal region and in the lower laminae (IV ... VII) of the superior colliculus. The findings are mainly ipsilateral. A direct projection to the dorsal part of the lateral geniculate could not be observed. By enzymhistochemic methods we localized the AchE intracellular in the rostral part of the area cuneiformis. After destruction of this area there was observed a clear diminishing of the AchE activity in the ventral lateral geniculate and in the area pretectalis. These results were confirmed by biochemical methods.

Acetylcholinesterase↗
PubMed1975

[Columnar organization of pyramidal cells of the visual cortex in the albino rat].

1. The arrangement of the pyramidal cells of the visual cortex has been investigated by light and electron microscopy in 36 albino rats. 2. It was shown, that the apical dendrites form bundles. The number of dendrites per bundle is about 5 in the lower lamina Vb and 7.5 in the upper lamina Va, the diameter of bundles is about 25.7 mum. The average distance between the centers of bundles is 76,4 mum, and between the peripheries 53.1 mum. 3. The results are compared with physiological and morphological findings. It was shown, that there is an agreement of diameter of bundles und their lateral branching dendrites with diameters of columns of cells and of terminal branchings of specific afferents. 4. The morphological results are graphically reconstructed.

Animals↗
PubMed1975

[Relais cells and afferent axons in the dorsal part of the lateral geniculate body in the albino rat under geometrical aspects].

1. The average volumes of dendritic domaines of relay neurons (P-neurons) were calculated and the quantitative relations to the neuronal elements situated in this area were investigated. Likewise we carried out measurements and calculations at the terminal parts of afferent axons, to find a conception concerning possible contacts between axons and P-neurons considering quantitative aspects. 2. The dendrites of one P-neuron are distributed in an area of about 0,008 mum3. In this area there are located somata of at least 120 other P-neurons and dendrites of altogether about 900 P-neurons. 3. The type-1-axons (cortical afferents) run almost linearly in the longitudinal system of the CGLd. Traversing a distance adequate to the diameter of a P-neuron (250 mum) the dendrites of 150 to 170 P-neurons may cross the course of one axon. At this distance the axon, however, has just set up about 50 boutons, thus synaptic contacts may be established with one third at most of the existing cells. A type-1-axon that is bifurcating in the entrance area into the CGLd is altogether of about 2000 mum in length and is able to develop about 420 presynaptic profiles. 4. The type-2-axons (retinal afferents) show a distinct terminal branching zone. The Golgi-Kopsch impregnated terminals of type-2a-axons are distributed in a space of 147000 mum3 capacity, the corresponding terminals of type-2b-axons in a space of 443000 mum3. The type-2a-axons having an average number of 23 boutons, may contact the dendritic branching zones of 25 P-neurons. There is a good reason to assume that type-2b-axons are in contact also with terminal dendritic parts of P-neurons. Thus the number of P-cells, which spread their dendrites into the terminal branching zone of one type-2b-axon may amount to 540. The average number of boutons of one type-2b-terminal, however, is only about 160. This means that synaptic contacts may be developed to the P-neurons-dendrites not exceeding 30% of them. 5. Various aspects of divergence of axon terminals in the albino rat's CGLd are discussed.

Animals↗
PubMed1975

[The rat visual cortex. Cytoarchitecture and stereotactic parameters].

In the present investigation the visual cortex of the albino rat was analyzed. On the basis of cytoarchitectonic criterions we can demarced the area striata (field 17) from a medial (field 18) and lateral (field 18a) lying peristriatic area. There are differences in the cortical structure not only between the striate and peristriate areae but also between field 18 and field 18a. In this publication we also present the visual cortex in stereotaxic coordinates on the basis of the stereotaxic atlas of FIFKOVA and MARSALA. Stereotaxic informations belonging the different fields of the visual cortex of the rat are not yet known, but they are very helpful for experimental investigations in this region of the brain.

Animals↗
PubMed1974

[Light and electron microscope investigation of axons and dendrites in the pars dorsalis of the corpus geniculatum laterale of the albino rat].

1. The neuronal elements of the GLD of the albinorat were investigated by Golgi-Kopsch and Golgi-Rapid methods. Furthermore the terminals of the tractus opticus were investigated by electron microscopy after eye enucleation. 2. The thalamo-cortical relay neurons have dendritic protrusions. These spine-like protrusions are to be found in the terminal parts of the dendrites. In contrast to spines in the pyramidal cells there is no thickening of the terminal part. Few relay cells have grape-like appendages in their branching zone. Only the initial segments of the axons of the P-neurons are visible. There is no evidence of recurrent collaterals. 3. The Golgi-type-2-neurons (interneurons, I-neurons) have less dendrites than the P neurons, but they are longer...

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