[Incidentaloma in 6 month old breastfed babies].
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Journal Article↗
Biomedical subjects
M J Azanza
Publications and source records attributed to M J Azanza.
[Fever without source in breastfed babies].
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Journal Article↗
Synaptic neurone activity under applied 50 Hz alternating magnetic fields.
The effect of 50 Hz alternating magnetic fields of 10-150 Gauss (1-15 mT) intensity on neurone synaptic activity for glutamate and acetylcholine has been studied. The applied 50 Hz alternating magnetic field does not modify the synaptic activity induced by glutamate or acetylcholine on neurones. It has been observed that both caffeine and glutamate induce similar effects, either stimulation or inhibition, on different neurone types. It is shown that applied 50 Hz alternating magnetic fields mimic the synaptic effect of glutamate. A mimic effect has also been observed between the induced effect by applying 50 Hz alternating magnetic field on neurones and the one induced by caffeine and glutamate on the same neurone. The application of Ringer solutions with different concentrations of Ca2+/K+ ions suggest that Ca2+ ions are involved in the elicited responses to either caffeine, glutamate or 50 Hz magnetic fields. Our conclusion is that the observed mimic induced effects for 50 Hz alternating magnetic fields, caffeine and glutamate on neurones corroborate that Ca2+ ions are the cytosolic effectors of the applied 50 Hz alternating magnetic fields interaction with neurone plasma membrane.
Acetylcholine↗
Distribution of NADPH diaphorase-positive neurons in the enteric nervous system of the rabbit intestine.
Nitric oxide (NO) has been proposed as an inhibitory transmitter in gastrointestinal muscle relaxation. We analyzed the distribution of nitric-oxide producing neurons in the rabbit intestine through nicotinamide-adenine-dinucleotide-phosphate-diaphorase histochemistry. By this reliable and convenient method, we visualized neuronal nitric-oxide-synthase, the enzyme responsible for nitric oxide generation, in the rabbit intestine. In the ileum and rectum, nitric-oxide-synthase-related diaphorase activity was present in the myenteric plexus ganglion cells, and in the nerve fibers in the internodal strand, secondary, and tertiary plexuses. These fibers were particularly abundant in the deep circular rather than in the outer longitudinal muscle layer. In the inner submucosal plexus, we found scarce labeled neurons. Labeled neural somata showed a range of sizes and shapes suggesting different functional roles. The present basic information is required to use the rabbit as an experimental animal in neurochemical NO enteric research.
Animals↗
Histochemical, immunohistochemical, and electron microscopy study of the caudal portion of the chicken intestinal nerve of Remak.
In order to deepen our knowledge of the different components of the chicken intestinal nerve of Remak (I.N.R.), we have studied it by means of histochemical, immunohistochemical and electron microscopy techniques to distinguish the different neurotransmitters. We have found cholinergic cell bodies, as well as acetylcholinesterase (AChE) positive neuronal fibers, forming part of the web that constitutes the I.N.R. in its caudal portion, with a higher density of neuronal bodies in the ganglia. We also observed catecholaminergic neuronal bodies and fibers, located fundamentally in the periphery of the nerve, and a low density of catecholaminergic cell bodies. With respect to the vasoactive intestinal peptide (VIP) and substance P (SP) positive peptidergic innervation, we found more abundant neuronal bodies positive for the V.I.P. than for S.P. Electron microscopy corroborated the results observed under the optic microscope, showing the various types of vesicles containing different neurotransmitters.
Acetylcholinesterase↗
Intrinsic innervation of a reptilian esophagus (Podarcis hispanica).
We study the esophagus of Podarcis hispanica through different methods to clarify the structure and affinities of its wall innervation. The acetylcholinesterase method reveals cholinesterase activity in two submucosal nervous plexuses, with an increasing degree of structural complexity in the reptilian esophagus, compared with amphibians. Noradrenergic innervation, detected through fluorescence induced by formol, widely spreads its network in both the myenteric and submucosal plexuses (around the blood vessels in the external submucosal plexus, and to the glandular lamina propria in the inner submucosal plexus). Immunohistochemistry for vasoactive intestinal peptide shows a widespread innervation, with neurons clustered in ganglia and also scattered through the VIPergic network, only at the myenteric plexus. Immunohistochemistry for substance P shows a rich innervation along the entire wall of the esophagus, more concentrated in its caudal region, around the blood vessels. Electron microscopy shows the enteric neuronal ultrastructure and its relationship with the esophagus wall.
Acetylcholinesterase↗
Cell membrane biochemistry and neurobiological approach to biomagnetism.
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Animals↗
Frog stomach enteric plexuses in culture: isolation, morphological characterization and bioelectrical recordings.
We have succeeded in the isolation, culture and morphological characterization of Rana ridibunda stomach enteric plexuses. We have furthermore obtained intra and extracellular bioelectric recordings from the explants in culture. The culture medium used (Eagle MEM), the collagenase digestion and the general culture conditions followed are similar to those applied to mammal enteric plexus explant cultures. The most striking difference is that the solutions were diluted to 70% in order to maintain the osmolar conditions required by the amphibian cells. Acetylcholinesterase, osmium tetroxide-zinc iodide- and para-formaldehyde-induced fluorescence methods reveal similar morphological images from the perivascular fibre plexuses. The different cell types observed by phase contrast light microscopy from the myenteric explants in culture have been identified by comparison with those revealed by the acetylcholinesterase method. The prevailing neurons show piramidal somas; other neurons are bipolar with oval somas and a third type shows oval somas tightly aligned, following sinusoidal courses. The intra and extracellular bioelectric recordings from the explants in culture show that the culture conditions we have applied preserve the electrophysiological properties of the neuronal membranes. These preliminary recordings will allow us to undertake the synaptic characterization of the gastrointestinal neurotransmitters in frogs.
Animals↗
The autonomic innervation of the liver and gallbladder of Podarcis hispanica.
The innervation of the liver and gallbladder of the lizard Podarcis hispanica has been studied by the following methods: a) demonstration of cholinesterase activity; b) FIF method for catecholamines; and c) immunohistochemistry for VIP. The hepatic parenchyma of the reptile's liver show hepatocytes arranged in regular rows of hepatic cords, the portal triad being typical of higher vertebrates (birds and mammals). Nerve fibers are found in the scarce connective tissue distributed among the hepatocytes. The innervation is restricted to the big branches of blood vessels and biliary ducts. It is represented by cholinergic, noradrenergic and VIPergic fibers. The gallbladder shows a well developed cholinergic plexus with pyramidal cells in the interconnection points of the fiber network. The noradrenergic and VIPergic plexuses are also more widely distributed in the gallbladder than in the liver.
Animals↗
Ultrastructural characteristics of anterior gut innervation of Gallus gallus.
The enteric nervous system of the bird's anterior gut is very well developed. Myelin fibres are seen accompanying the nervous trunks up to the mucous layer. Glial cells duplicate the number of neurons in the myenteric plexuses. Their number decreases at the submucous plexuses, but it is always higher than the neurons. Isolated neurons are widely spread in the circular muscle coat accompanying the nervous trunks which can be inter and intrafascicularly located. Direct synaptic contacts with the soma neuronal membranes are very often seen. We have never observed synaptic specializations. The most prominent varicosities either in the peripheric nervous trunk axons or directly laying on the soma membranes are those containing peptidergic or mixed vesicles of cholinergic and peptidergic types. The neurons show big nuclei of different size and shape. Neighbouring smooth muscle cells show abundant caveolae near the nervous elements. Although we have not observed close contacts with glands, thin axon bundles spread near the glandular cells of the mucous layer.
Animals↗
Steady magnetic fields mimic the effect of caffeine on neurons.
We have observed that steady magnetic fields (SMF) of 1160 and 2600 gauss (G) mimic the inhibitory and excitatory actions of caffeine on neurons. We had observed that isolated mollusc neurons exposed to SMF were either inhibited or excited by mechanisms that appear Ca2+-dependent. Our results with caffeine corroborate that changes in Ca2+ kinetics underlie the electrophysiological membrane changes observed in neurons exposed to SMF.
Action Potentials↗
The autonomic innervation of the liver and gallbladder of Rana ridibunda.
1--The innervation of the liver and gallbladder of Rana ridibunda has been studied by the following methods: (a) demonstration of cholinesterase activity; (b) FIF method for catecholamines; (c) immunohistochemistry for VIP and (d) electron microscopy. 2--The hepatocytes are arranged in regular rows of hepatic cords, very little connective tissue is distributed in the parenchyma, the innervation being restricted to the big branches of blood vessels. 3--Well defined cholinergic and adrenergic plexuses surround the hepatic arteries, portal veins and biliary ducts. The VIPergic innervation is scarce in the liver but a richly branched plexus spreads in the wall of the gallbladder. 4--Cholinesterase-positive cells are widely distributed accompanying the nerve trunks of the gallbladder. The innervation distribution is prominent in the portion of the gallbladder next to the hepatic hilus. 5--A population of melanin-storing cells besides free melanin granules are present in the liver parenchyma and are prominent in the gallbladder where the melanocytes are disposed in close contact with blood vessels and nerve structures. We have observed that the number of these visceral melanocytes considerably increases in winter, particularly in the liver.
Acetylcholinesterase↗
Intrinsic and extrinsic innervation of the amphibians esophagic myenteric plexuses.
The innervation of Rana ridibunda esophagus myenteric plexuses has been studied by the following methods: demonstration of cholinesterase activity; FIF method for catecholamines; immunohistochemistry for VIP, SP and SOM, and conventional electron microscopy. The cholinergic innervation is important in the esophagus wall where, in addition to the well known extrinsic component, there is a rich intrinsic plexus with cells and fibres widely distributed. The esophagus, together with the intestine, are the Rana gut portions where the adrenergic component is more broadly expressed. The adrenergic innervation seems to be almost entirely of extrinsic origin. We have shown that, for the tested peptides, there is an intrinsic innervation represented by VIP, SP and SOM like plexuses. We do not discard nonetheless an extrinsic component. The ultrastructure reveals the morphological characteristics of the enteric neurons as well as the fine inter-relationships between the nervous elements and the functional components of the esophagic wall.
Animals↗
The vagal contribution to the rat liver innervation: a demonstration with the cobalt impregnation method.
The contribution of the vagus nerves to the innervation of the liver has been studied with the cobaltous chloride impregnation method. With this method we have demonstrated that the fiber plexus in the rat hepatic parenchyma, that we had previously described and stained for acetylcholinesterase, is of a nervous nature and of vagal origin. Our results show that branches from the vagus spread abundantly with the connective tissue at the capsule. From this peripheral location, the fibres expand deeply through the parenchyma in close contact with the hepatocytes towards the central veins. Other branches run with the interlobular connective tissue, distributing to the portal veins, hepatic arteries and biliary ducts. They also have lateral branches which penetrate into the parenchyma.
Acetylcholinesterase↗
Melanin storing cells in anuran gut.
1. The location, distribution and morphological characteristics of the pigment cells found in the frog gut are described. 2. The pigment cells show long and large protoplasmic projections. At the ultrastructural level, the nucleus is elongated with prominent nucleolus and dense marginal chromatin. The cytoplasm is full with pigment granules (2500-7500 A) and typical premelanosome structures have been observed. 3. The pigment cells number is higher in the esophagus and large intestine than in the stomach or small intestine and the pigment cells are always located in close contact with blood vessels and nervous structures (ganglia and fibres). 4. We have observed that the pigment content depends upon seasonal variations, increasing during the cold months. 5. We have demonstrated by histological methods that the cells pigment content is melanin. 6. According to their morphological and tinctorial characteristics the anuran gut melanin storing cells are similar to the skin epidermal melanocytes.
Animals↗
The autonomic innervation of Rana ridibunda intestine.
1. The innervation of Rana ridibunda intestine has been studied by the following methods: (a) demonstration of cholinesterase activity; (b) FIF method for catecholamines; (c) immunohistochemistry for VIP, SP and SOM, and (d) conventional electron microscopy. 2. The intrinsic intestinal innervation is represented by cholinergic-, VIPergic-, SP- and SOM-like plexuses. The intestinal adrenergic component is of extrinsic origin. 3. The intestinal peptidergic innervation is the most developed, the large intestine being the portion where the studied peptidergic plexuses are more widely distributed. 4. Against a poorly developed cholinergic/adrenergic innervation, it seems that there is a predominant peptidergic innervation in the amphibians intestine wall. 5. Taking into account that amphibians sacral parasympathetic as well as sympathetic innervation development are limited, it could be considered that in vertebrates the intestinal peptidergic innervation is phylogenetically earlier and hence better developed.
Adrenergic Fibers↗
The autonomic innervation of the rat diaphragm.
The innervation of the diaphragm has been studied by three methods--cobalt tracing of the nerves, demonstration of cholinesterase activity and fluorescence microscopy for catecholamines and VIP. The cobalt method reveals the peripheral nerve fibers with a sharpness similar to that shown at the level of the central nervous system where this method has so far been more widely applied. The cobalt method helps to outline the distribution pattern of the nerve fibers and it can be of particular interest at the level of the viscera in order to show the different sources of the axons. Fibers giving a positive response to cholinesterase staining are shown at the level of the motor end plates and surrounding the blood vessels. It is suggested that the axons of phrenic origin contribute to the motor end plates while those coming from the vagus are distributed along the connective tissue surrounding the vascular system. Noradrenergic innervation is scarce, appearing as fine varicosities around the vascular beds. The VIPergic fibers are probably, together with the cholinergic ones, the most widespread. They are distributed among the muscle fascicules as well as being in close connection with the blood vessels.
Adrenergic Fibers↗
The enteric nervous system of Rana ridibunda stomach.
The innervation of Rana ridibunda stomach has been studied by the following methods: demonstration of cholinesterase activity; FIF method for catecholamines; immunohistochemistry for VIP; SP and SOM and conventional electron microscopy. The cholinergic innervation is important in the stomach wall where in addition to the intrinsic plexuses there is an extrinsic contribution coming with the vagus nerve. The density of the fibres decreases towards the pyloric sphincter. The adrenergic innervation seems to be almost entirely of extrinsic origin. Fine networks have been localized at the myenteric and submucosal plexuses. The fibres density increases at the pylorus. At the myenteric plexus, apart from the cholinergic neurons, we have found VIP and SOM like cells. The VIP like plexus is very well developed. A SOM like plexus is also present but with scarce fibres in comparison with the VIPergic one. The submucosal plexus is exclusively made by nervous fibres of the types described for the myenteric one. We have got positive immunoreactivity for SP only on the fibres. They are scarce in the stomach wall, only at the pyloric region their density increases. We describe the ultrastructural morphological characteristics of the enteric neurons as well as the fine inter-relationships between the nervous elements and the functional components of the stomach wall.
Animals↗