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Biomedical subjects

J Cano

Publications and source records attributed to J Cano.

At least 163 records · Page 9Linked to original sources
PubMed1988

Changes in biogenic amines in rat hippocampus during development and aging.

The effects of postnatal development and aging on the concentration of dopamine, noradrenaline, serotonin and their principle metabolites have been studied in the hippocampus of the rat. During development the concentration of dopamine increases 1.5 fold during the first 90 days. 3-methoxytyramine was found in low concentrations. The homovanillic acid and DOPAC concentrations showed no changes apart from a decrease at day 15 and an increase at day 8, respectively. From birth up to 30 months, the noradrenaline concentration increased by a factor of about 10. Their metabolites each showed a different profile. The concentration of tryptophan was always the highest among the compounds studied. It decreased from birth to day 15, while the concentration of serotonin and 5-hydroxyindolacetic acid increased 3 and 5 fold respectively during this time. However, 5-hydroxytryptophan and 5-hydroxytryptophol concentrations were very low and unchanged at all stages. These findings led to the conclusion that the neurotransmitters: noradrenaline and serotonin, are developed in the hippocampus during the first three months. During aging, the serotonin concentration is increased without significant change in the other compounds studied.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1988

[Degradation of human hair in vitro by Trichophyton mentagrophytes].

The degradation "in vitro" of human hair, invaded by the dermatophyte Trichophyton mentagrophytes was studied by means of scanning and transmission electron microscopy. The digestion of the hair started as well in the cuticle as in the cortex, in the regions with low content of keratin, especially in the intercellular spaces. The exocuticle and epicuticle were the most resistant parts of the cuticle in fungal degradation, due to its high content in cystine. In the cortex the macrofibrils were first separated from each other and later attacked on the surface and the interior, arriving to be almost completely degraded. At the end only pigmented granules and rests of membranes could be observed. After a month the hair was almost entirely destroyed probably due to an enzymatic process although some mechanical alteration could also be observed.

Child↗
PubMed1987

Complex convolutions in neurons of the dorsal lateral geniculate nucleus of the normal albino rat.

The postnatal development of complex convolutions (CCs) of the dorsal lateral geniculate nucleus (LGNd) in normal rats has been studied quantitatively with light microscopy. We report that immature neurons do not contain these scarcely understood organelles, since they can be seen for the first time in very few, mature neurons of the 30 day rat; their number constantly increases during the following 4 months. These cytoplasmic inclusions can be equally seen in the aged rat. CCs are present in neurons of all sizes, except the smallest, which correspond to the interneuron population. Although, morphologically, CCs of the LGNd of the rat are similar, but not identical, to the cytoplasmic multilaminated bodies of the cat, intermediate forms are described.

Animals↗
PubMed1987

Age-related changes of serotonin and its metabolites content in the visual system of the rat.

Measurements have been taken of the serotonin and its metabolites (tryptophan, 5-hydroxytryptophan, 5-hydroxy-3-indolacetic acid and 5-hydroxytryptophol) in each structure of the geniculate and extrageniculate visual system of rats aged between 3 and 30 months. The concentration of tryptophan was the highest of all compounds studied. Its increase during ageing is statistically significant in the lateral geniculate and posterior thalamus. 5-HTP concentration was very low and in some cases not detectable. 5-HT concentrations and its principal metabolite, 5-HIAA, showed a different profile in each brain structure. The lateral geniculate and visual cortex showed statistically significant changes, but with opposite results. In the lateral geniculate the 5-HT and 5-HIAA concentrations were increased during the ageing period. However, in the visual cortex the 5-HT and 5-HIAA concentrations decreased in the same period. These age-related changes were not seen in the superior colliculus and posterior thalamus as in the 5-HT levels as in the 5-HIAA. 5-hydroxytryptophol was always found in low concentration. These results suggest age-related changes in the geniculate visual system.

Aging↗
PubMed1987

[Recurrent infection of the urinary tract in girls].

A group of 18 girls, studied in a period between 1979 and 1985 with recurrent urinary tract infections (RUTI), with at least three culture documented episodes of bacteriuria in the previous year and without radiologic evidence of urinary tract abnormality is described. Incidence was 6.1% amount a selected group of 295 girls with urinary tract infection. The period of follow-up was between 2 and 6 years (X 3.33). Symptomatology was light. No predominance of urinary symptoms were found. E. coli was the most frequent germ isolated. The number of recurrences/year/girl were significantly lower with prophylactic treatment and with years of evolution. Renal damage was not found. Vesicoureteral reflux appeared in two girls only. They had a benign course and a good prognosis. Reduction of aggressive investigation in this group of patients is proposed.

Child↗
PubMed1986

Quantitative cellular changes during postnatal development of the rat dorsal lateral geniculate nucleus.

Quantitative changes in cell number during development of the dorsal lateral geniculate nucleus were determined using semithin serial sections of tissue obtained from 28 rats on postnatal day 0, 5, 8, 10, 20, 30, 90 or 165. Our results show three phases of postnatal development in the rat dorsal lateral geniculate nucleus: phase 1 from birth until eye opening, which occurs around the 12th day in these litters; phase 2 from eye opening through stabilization of neuron number on the 30th postnatal day, and phase 3 from that event until adulthood. During the first period increases in neuron number and in glial cell number are found accompanying a nearly seven-fold increase in dorsal lateral geniculate nucleus volume. Phase 2 includes a high incidence of neuronal cell death and a continuous increase in the number of glial cells. The third phase is characterized by a stabilization in the number of neurons, although the glial cell number continues to increase. Neuronal density decreases exponentially throughout the postnatal life of the rat, while the density of glial cells remains relatively stable over the period of study. The postnatal phenomenon of an initial increase in neuron number followed by a period of neuron death may be related to modulating and plastic functions which occur in the rat dorsal lateral geniculate nucleus before a stable neuronal population is achieved on the 30th postnatal day.

Aging↗
PubMed1986

A morphologic analysis of neurons and neuropil in the dorsal lateral geniculate nucleus of aged rats.

Light and electron microscopy were used to investigate the morphology of neuropil and neuronal cell bodies of the dorsal lateral geniculate nucleus (LGNd) of aged rats. Light microscopic examination reveals that, despite the optic tract showing signs of degeneration, the LGNd is scarcely affected. Thus, a slight but significant reduction in the diameters of both soma and nuclei is observed in aged neurons of the LGNd. Ultrastructural analysis demonstrates a few degenerating profiles of the neuropil. Neurons resembling relay cells exhibit typical features of aged neurons. Cells showing a very infolded nucleus, most of the ER cisternae connected with the nuclear envelope, abundant free polyribosomes and subsurface cisterns associated with mitochondria are similar to interneurons of adult rats. Therefore, aging and partial loss of visual input appear to induce small changes in the morphology of most of LGNd neurons.

Aging↗
PubMed1986

Morphological changes in the retina of ageing rats.

This paper deals with the morphological changes in the retina with ageing. The most significant result was a decrease in the thickness of the aged retina compared to that of the controls. Although all layers underwent reduction, the most affected were the outer nuclear layer (that was reduced to 90%) and the ganglion cell number (which was reduced to 40%). The surviving photoreceptors and ganglion cells showed structural changes. In the photoreceptors we found a disappearance of the outer segments, and in many instances the inner segment was in direct contact with microvilli from the pigment epithelium. In the ganglion cells we found an increase in Golgi apparatus, however, not at a uniform rate but to different degrees in the different cells.

Aging↗
PubMed1986

The change with age in biogenic amines and their metabolites in the striatum of the rat.

The changes in the content of the biogenic amines and their metabolites in the striatum of the rat during the aging period (3-30 months) have been studied. The maximum levels of dopamine (DA) have been found at 6 months of age and this concentration is maintained until 24 months. Between 24 to 30 months there is a decrease in the concentration of this compound. At that time, there is a slight increase in 3,4-dihydroxyphenyl acetic acid (DOPAC) and homovanillic acid (HVA) concentration, the main metabolites of DA, which suggests a slight increase in DA metabolism. The 3-methoxytyramine (3-MT) concentration also increases at this time. The maximum concentration of noradrenaline (NA) was also found at 6 months of age. Tryptophan has the maximum concentration after DA and this is maintained over the life-span of the rat. The concentration of serotonin (5-HT) is high and does not change during this period. However, the concentration of 5-HT, as occurred with DA, decreased between 24 and 30 months. Also the DA/5-HT ratio does not change during the period studied.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1985

Stability of the neuronal population of the dorsal lateral geniculate nucleus (LGNd) of aged rats.

The variations, with aging, of both neuronal and glial populations of the rat LGNd have been studied quantitatively. Our results show a stability of the total number of neurons of the rat LGNd with aging; this, plus the constant increase of the rat LGNd volume throughout rat life, causes the neuronal density to decrease slowly. Our data prove the necessity of determining the total number of neurons, not just neuronal density, in order to find out the actual evolution of the neuronal population with aging. Both glial cell number and density show an increase throughout rat life.

Age Factors↗
PubMed1985

An electron microscopic study of astroglia and oligodendroglia in the lateral geniculate nucleus of aged rats.

The ultrastructural features of glial cells in the lateral geniculate nucleus of aged rats have been studied. Abundant filaments as well as heterogeneous dense bodies are observed in the majority of astrocytes. They frequently surround both axons and nerve terminals showing signs of degeneration. In addition, some degenerating myelinated axons are seen in phase suggestive of engulfment by astrocyte processes. Oligodendrocytes display broad processes containing an organelle-rich cytoplasm and a continuity between their plasma membrane and the outer myelin lamellae which partially ensheath the adjacent axons. Multivesicular bodies and pleomorphic dense inclusions, composed of amorphous material as well as laminated structures, are also present in oligodendrocytes. The significance of these morphological features is discussed in relation to process of normal ageing.

Aging↗
PubMed1985

Effects of high doses of iodide on thyroid secretion: evidence for the presence of iodinated membrane tubulin.

The transient inhibitory effect on thyroid secretion produced by high doses of iodide was investigated with respect to changes in the level of in vivo iodination of membrane tubulin. Iodinated tubulin, characterized by gel electrophoresis, immunoprecipitation, and peptide mapping, was shown to be associated with a thyroid membrane fraction, and totally absent from cytoplasmic proteins. The administration of an acute dose of 5 mg KI, although it inhibited thyroid secretion (as shown by an increase in TSH), did not have a significant effect on the level of iodination of membrane tubulin. Thus, the observed inhibition of thyroid secretion is probably unrelated to the level of iodination of tubulin. Although its function is not known at present, iodinated tubulin is probably involved in membrane-related phenomena.

Animals↗
PubMed1985

Ag-NOR chromosomal association patterns in Rattus rattus (Rafinesque, 1814) and Rattus norvegicus (Berkenhout, 1796) from the southern Iberian peninsula.

A high frequency of satellite association phenomena in a number of specimens of Rattus rattus and R. norvegicus, captured on the coastal fringe of Málaga province (Southern Spain), was found. Only Ag-NOR bearing chromosomes participated in associations in both species. R. rattus is characterized by 14/18 heterologous and R. norvegicus by 5/5 and 13/13 homologous association types.

Animals↗
PubMed1984

Intramitochondrial inclusions in maturing and senescent muscle cells of rat myocardium.

Intramitochondrial myelin-like structures were found in ventricular myocardial cells of the rat heart. These inclusions were found in both the first 2 postnatal weeks and in senescent stages. The origin of such myelin-like structures could be related to an age-dependent metabolic change, specifically to an inability to oxidize long-chain fatty acids described in both periods.

Aging↗
PubMed1982

Influence of innervation on the levels of noradrenaline and serotonin in the circumvallate papilla of the rat.

The levels and the distribution of monoamines within the rat circumvallate papilla have been studied. Noradrenaline was found in the connective tissue underlying the taste buds, whereas serotonin was located in the basal area of the gustatory epithelium but not inside the taste buds. Following denervation, noradrenaline levels decreased and serotonin levels increased. These results suggest that both neurotransmitters may have some mutual interaction in modulating transmission at the papilla.

Animals↗
PubMed1982

Postnatal development in the serotonin content of brain visual structures.

The serotonin content in various structures of the geniculate and extrageniculate visual system throughout the postnatal development period has been investigated. The results indicate that in all structures studied there is a increase in the content of serotonin. However, each structure showed a different developmental profile of serotonin levels.

Aging↗