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Biomedical subjects

A Toledano

Publications and source records attributed to A Toledano.

At least 73 records · Page 4Linked to original sources
PubMed1980

Distribution of peripherally stained neurons by the colloidal iron histochemical method in albino rat cerebral cortex. A quantitative study.

A few stained neurons were demonstrated in several cortical areas by the Colloidal Iron method. The intense positive histochemical reaction was located surrounding the perikaryon and some neuronal branches. A quantitative study demonstrated that the largest percentage of stained neurons was found in III, IV and V layers of the visual and auditory cortex. The number of stained neurons in the auditory cortex was greater than in the visual cortex. Statistically significant differences (Student's t-test) were obtained between layers I, II, III and VI of both cortical areas. In other cortical areas studied there were no stained neurons (area insularis ventralis, area entorhinalis and area piriformis).

Animals↗
PubMed1980

A comparative histochemical study of diphosphatenucleosidases and thiaminepyrophosphatase in the mammalian hypothalamus.

NDPase and TPPase activities were detected by histchemical techniques in the hypothalamus of rat, cat and man. Both enzymatic activities were exhibited by neurons and glial cells, the latter hydrolyzing NDP more actively than TPP. Enzyme hydrolysis of NDP and TPP was activated by imidazole and inhibited by noradrenaline, L-DOPA, L-cysteine and KF. The results could be explained by postulating a common enzyme (probably two iso-enzymes) for NDP and TPP hydrolysis. The location of NDPase and TPPase in synaptic sites suggests that these enzymes may be involved in neurotransmission. A possible system for the intracellular transport of enzymes from their site of manufacture is put forward.

Acid Anhydride Hydrolases↗
PubMed1979

Histochemical characteristics of diphosphate nucleoside consumption in cat and rat nervous system.

Consumption of diphosphate nucleosides is investigated by histochemical methods in rat and cat nervous system. Results show NDP-ase is effectively in histological sections from animals previously perfused with glutaraldehyde or formaldehyde. Histochemical reaction is increased in presence of Ca++, Mg++, Mn++ or imidazole and inhibited by L-DOPA and Noradrenaline in incubation medium. A comparative study of TPP-ase and NDP-ase activities to dilucidate the identity of both enzymes is described.

Acid Anhydride Hydrolases↗
PubMed1979

Morphological and cytochemical study of a hypothalamochiasmatic perivascular neuronal system.

The topographical localization and some cytochemical characteristics of groups of perivascular neurons in the hypothalamus and in the optic chiasma have been studied. In the anterior hypothalamic area there are neuronal groups located around the blood vessels which penetrate the optic chiasma still associated with neurons. These perivascular neurons show some characteristics similar to those observed in neurosecretory hypothalamic neurons, but differ from them in that they show a greater intensity of thiaminopyrophosphatase and nucleoside-diphosphataseactivities. It is suggested that these neuronal groups may constitute a special hypothalamochiasmatic-perviscular-neurosecretory system (H. Ch. P. N. S.).

Acetylcholinesterase↗
PubMed1978

Glycoproteins and polyanions in the synapses of rat and mouse central nervous system.

In the present work, it is investigated the location and characteristics of receptors for Con A in synapses of rat and mouse central nervous system. Negatives charges of synaptic surface are also studied. It is observed the presence of glycoproteins on synaptosomal plasma membrane. Presence of negatives charges homogenously distributed all over the synaptosome surface is also notice. These negative charges are revealed by Colloidal Iron, FeOH++cation and cationized Ferritin. Enzymatic extraction experiments suggest that presence of sulphated mucopolysaccharides.

Animals↗
PubMed1978

Diaminobenzidine oxidation in cerebellar histological sections.

Cerebellar histological sections were incubated in media containing 3,3'-diaminobenzidine (DAB). Microscopic observation showed the presence of oxidated DAB in all cerebellar cells. Said oxidation of DAB in the cerebellar structures was produced in the absence, as well as in the presence, of exogenous H2O2 in the incubation medium. The erythrocytes existent in the blood vessels were capable of oxidating more intensely the DAB when H2O2 was present in the incubation medium. When the sections were pretreated and incubated with CNK, sodium azide and perodic acid, the oxidation of DAB was not produced. The observation with electron microscope showed that the DAB oxidation is produced in mitochondria, coated vesicles, and lysosomes. The possible mechanisms intervening in the oxidation of DAB in cerebellar structures are discussed.

3,3'-Diaminobenzidine↗
PubMed1978

Evidences for the existence of glycoproteins and mucopolysaccharides metabolic cycles in the cerebellum of birds and mammals.

Cerebellum glycoproteins of rats and ducks are studied using sugar-specific agglutinins. It is used the Con A-Peroxidase-DAB technique described by Bernhard and Avrameas (1971). Other agglutinins (Tetragonolobus Purpureus Lectin, Wheat Germ Agglutinin and Soybean Agglutinin) fixed to Peroxidase according to the technique of Gonatas and Avrameas (1973) are also used. The techniques for mucopolysaccharides as described Martínez-Rodriguez et al., (1976) are carried out as well. By means of all these techniques, results that suggest the existence of metabolic cycles in Purkinje cells are obtained.

Animals↗