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Biomedical subjects

L Tóth

Publications and source records attributed to L Tóth.

At least 109 records · Page 6Linked to original sources

[Na-glutamate sensitive neurons in the area postrema of the rat (author's transl)].

A single subcutaneous injection of monosodium-L-glutamate induces severe ultrastructural alterations in certain AChE positive parenchymal cells of the Area postrema of the adult rat. Signs of cellular degeneration include massive intracellular edema, swelling of mitochondria, vacuolization of the cisternae of the rough endoplasmic reticulum and marked alterations in the chromatin pattern of the nucleus. Identification of these cells as neurons is based on the presence of axosomatic synapses.

Animals↗

[Analysis of histochemical changes caused by acute Wofatox poisoning in a model experiment].

Effect of Wofatox on the central nervous system, striated muscles and on the myocardium of rats has been studied by the aid of light- and electron microscopic histochemistry. A single intraperitoneal injection of LD50 of Wofatox resulted in a total inhibition of the activity of histochemically demonstrable acetyl-cholinesterase in the central nervous system. Each striated muscle fiber has shown different sensitivity to the inhibitor, but enzyme activity of end motor plates could not be totally inhibited. In lethal acute intoxication ultrastructural changes of the myocardiuim have shown characteristic features of cardiomyopathy.

Acute Disease↗

Structural changes in the heart due to mechanical perfusion.

Acute myocardial damage such as epicardial, intramural and subendocardial haemorrhages and oedema are known to occur after mechanical perfusion. The results of animal experiments showed that local circulatory disturbances (hypoperfusion, hypoxia) due to mechanical damage of the blood (erythrocyte aggregation, denaturation) and or lasting hypoperfusion (microcirculatory hypoxia) are responsible for the acute lesions. In addition, the results offer a morphological explanation for the postperfusion heart failure.

Animals↗

Distribution and origin of acetylcholinesterase activity in the capillaries of the brain.

Areas containing AChE-positive capillaries were mapped in the brain of the cat and the guinea pig. Regions with AChE-positive capillaries mostly also contain neuronal elements with AChE activity. Electron-microscopical cytochemistry revealed localization of AChE in basement membranes of endothelial cells and pericytes very often in continuity with activity of the extracellular space. Intraendothelial AChE activity was seen only in pinocytic vesicles. The vascular AChE is thought to be of neuronal origin since no cytochemical evidence has been obtained for a synthesis of this enzyme in endothelial or other non-neuronal cells in the CNS.

Acetylcholinesterase↗

[Ultrastructural localization of the acetylcholinesterase (AChE) activity in the diaphragm of the rat embryo (author's transl)].

Electron histochemistry revealed intense AChE activity in the diaphragm of 15 days old rat embryos. The reaction product was localized to the perinuclear cisterna and the cisternae of the sarcoplasmic reticulum of myoblasts. The development of myoneural contacts at day 17 of gestation was preceded by the appearance of AChE activity of muscle cells. Sarcoplasmic cisternae and vesicles in the subjunctional sarcoplasm may play an important role in the development of the AChE activity of the postjunctional sarcolemm.

Acetylcholinesterase↗

Topographic analysis of AChE-positive Renshaw elements: a light- and electronmicroscopic histochemical study on the morphological basis of recurrent inhibition.

Light and electron microscopic structures of Renshaw elements as the morphological basis of the recurrent inhibition were studied by means of the histochemical localization of AChE. Renshaw elements were identified as periodically repeating bulbous dendritic dilatations of AChE-negative interneurons, equipped with numerous AChE-positive motoneuronal axon collaterals. Cumulative patterns obtained by analyzing consecutive sections from segment L5 of the cat spinal cord show that the area of the most frequent occurrence of Renshaw elements nearly coincides with the dendritic arborization of the 3. type interneuron described by MATSUSHITA. The role of the Renshaw elements in recurrent inhibition is supported by the fact that they occur in largest number in those areas of the ventral horn where the Renshaw inhibition can be elicited electrophysiologically.

Acetylcholinesterase↗