Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 72
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Reprod Biomed Online ; 28(2): 246-50, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24365020

RESUMEN

Tubulin is a protein constituent of cytoskeletal microtubules, closely related to sperm motility. However, the changes in tubulin distribution following capacitation and acrosome reaction are poorly understood. This study immunolocalized and quantified the expression of α-tubulin in fresh, capacitated and acrosome-reacted samples. Immunocytochemical data showed that in capacitated and acrosome-reacted spermatozoa, α-tubulin is labelled throughout most of the flagellum (⩾66.66%). However, the mean α-tubulin-labelled area in these samples was significantly lower than in fresh samples (P<0.05). Thus, there are different sperm clusters distinguished by their α-tubulin immunoreactivity and this could be directly linked to structural changes following capacitation and acrosome reaction.


Asunto(s)
Reacción Acrosómica/fisiología , Capacitación Espermática/fisiología , Espermatozoides/fisiología , Tubulina (Proteína)/metabolismo , Análisis por Conglomerados , Humanos , Inmunohistoquímica , Masculino , Microscopía Fluorescente , Tubulina (Proteína)/inmunología
2.
Radiologia ; 56(5): 463-71, 2014.
Artículo en Español | MEDLINE | ID: mdl-25016436

RESUMEN

Eponyms reflect the history of medicine, of disease, and of physicians, but eponyms also reflect the history of the societies in which these physicians lived. Both loved and hated, eponyms are at the center of an interminable debate about whether they should continue to be used or whether they should disappear, and this debate has become more intense since some scientific societies have purged their terminologies of eponyms related to Nazism. Eponyms abound in conventional musculoskeletal radiology. In this article, rather than attempt an exhaustive review of all these eponyms, we take a few representative examples to illustrate the contributions of eponyms to medicine and the history of medicine.


Asunto(s)
Epónimos , Radiología , Huesos , Civilización , Historia de la Medicina , Humanos , Mitología , Nacionalsocialismo
3.
J Fish Biol ; 82(3): 856-76, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23464548

RESUMEN

This study provides data on the genetic structuring of the pipefish Syngnathus abaster in the western Mediterranean and Adriatic Seas. A total of 109 specimens were collected in brackish-water biotopes. The control region and three other regions of the mitochondrial genome were analysed. The most relevant result was the high genetic structuring found by Bayesian inference (BI), maximum likelihood (ML) and network analyses, which were consistent in showing three well-separated clusters of S. abaster populations. Furthermore, BI and ML did not support the monophyly of the taxon S. abaster. These results suggest the occurrence of a species complex in the study area, whose differentiation may have occurred since the Pleistocene. The results also show a very high genetic variability at the inter-population level, with no shared haplotypes among sites. Evolutionary forces due to the fragmented nature of the brackish-water habitats may account for the high genetic divergence found among the groups and populations. Finally, although dispersal by rafting over long distances may occasionally occur, this study suggests linear stepping-stone model of colonization to be most likely. The complexity of the results obtained suggests that further studies are needed to elucidate the phylogeny of S. abaster.


Asunto(s)
ADN Mitocondrial/genética , Evolución Molecular , Variación Genética , Filogenia , Smegmamorpha/genética , Animales , Teorema de Bayes , Haplotipos , Funciones de Verosimilitud , Mar Mediterráneo , Análisis de Secuencia de ADN
4.
Arch Microbiol ; 192(12): 1023-30, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20878147

RESUMEN

The aim of this research was to show the mathematical data obtained through the correlations found between the physical and chemical characteristics of casing layers and the final mushrooms' properties. For this purpose, 8 casing layers were used: soil, soil + peat moss, soil + black peat, soil + composted pine bark, soil + coconut fibre pith, soil + wood fibre, soil + composted vine shoots and, finally, the casing of La Rioja subjected to the ruffling practice. The conclusion that interplays in the fructification process with only the physical and chemical characteristics of casing are complicated was drawn. The mathematical data obtained in earliness could be explained in non-ruffled cultivation. The variability observed for the mushroom weight and the mushroom diameter variables could be explained in both ruffled and non-ruffled cultivations. Finally, the properties of the final quality of mushrooms were established by regression analysis.


Asunto(s)
Agaricus/crecimiento & desarrollo , Modelos Biológicos , Microbiología del Suelo , Suelo/química , Cocos , Plantas , Sphagnopsida , Madera
5.
Physiol Meas ; 30(9): 885-902, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19636086

RESUMEN

Surface recording of electroenterogram (EEnG) is a non-invasive method for monitoring intestinal myoelectrical activity. However, surface EEnG is seriously affected by a variety of interferences: cardiac activity, respiration, very low frequency components and movement artefacts. The aim of this study is to eliminate respiratory interference and very low frequency components from external EEnG recording by means of empirical mode decomposition (EMD), so as to obtain more robust indicators of intestinal pacemaker activity from the external EEnG signal. For this purpose, 11 recording sessions were performed in an animal model under fasting conditions and in each individual session the myoelectrical signal was recorded simultaneously in the intestinal serosa and the external abdominal surface in physiological states. Various parameters have been proposed for evaluating the efficacy of the method in reducing interferences: the signal-to-interference ratio (S/I ratio), attenuation of the target and interference signals, the normal slow wave percentage and the stability of the dominant frequency (DF) of the signal. The results show that the S/I ratio of the processed signals is significantly greater than the original values (9.66 +/- 4.44 dB versus 1.23 +/- 5.13 dB), while the target signal was barely attenuated (-0.63 +/- 1.02 dB). The application of the EMD method also increased the percentage of the normal slow wave to 100% in each individual session and enabled the stability of the DF of the external signal to be increased considerably. Furthermore, the variation coefficient of the DF derived from the external processed signals is comparable to the coefficient obtained using internal recordings. Therefore, the EMD method could be a very useful tool to improve the quality of external EEnG recording in the low frequency range and therefore to obtain more robust indicators of the intestinal pacemaker activity from non-invasive EEnG recordings.


Asunto(s)
Relojes Biológicos/fisiología , Electromiografía/métodos , Intestinos/fisiología , Algoritmos , Animales , Perros , Electrodos , Electrofisiología , Motilidad Gastrointestinal/fisiología , Procesamiento de Señales Asistido por Computador
6.
An Pediatr (Barc) ; 69(3): 239-43, 2008 Sep.
Artículo en Español | MEDLINE | ID: mdl-18775269

RESUMEN

INTRODUCTION: Glutaric Acidaemia type I (GA-I) is an autosomal recessive progressive neurodegenerative inborn error of metabolism caused by deficient activity of the enzyme glutaryl-CoA dehydrogenase (GCDH). In most cases, the diagnosis is established biochemically by the detection of glutaric acid and 3-hydroxy glutaric acid in urine and glutarylcarnitine in plasma. Patients excreting small amounts of glutaric acid may be overlooked. OBJECTIVE: To investigate the value of expanded newborn screening by adding the measurement of urine glutarylcarnitine to conventional chromatography-mass spectrometry (GC-MS) in the diagnosis of GA-1. MATERIAL AND METHODS: We report clinical and biochemical data in 5 GA-I patients diagnosed in our Hospital. Details regarding biochemical diagnosis are emphasised and the absence or presence of symptoms was correlated with neuroimaging findings, age at diagnosis and treatment. RESULTS: Two patients showed high glutarylcarnitine levels in plasma and were identified by routine newborn GC-MS screening. Following early appropriate treatment they are asymptomatic 6 years later. Two patients with delayed diagnosis displayed neurological sequels in spite of treatment. The remaining patient, who presented with encephalopathic episode at age 8 months showed normal glutarylcarnitine levels in routine plasma GC-MS but high urine glutarylcarnitine levels in a retrospectively screened urine sample from the newborn period. CONCLUSIONS: Early treatment seems to positively influence the clinical evolution of GA-I patients. Thus, improving the identification of GA-I represents an important diagnostic challenge. The urinary excretion of glutarylcarnitine is a specific biochemical marker of GA-I and allows the identification of patients without glutaric aciduria and with normal plasma acylcarnitine profiles.


Asunto(s)
Errores Innatos del Metabolismo de los Aminoácidos/diagnóstico , Errores Innatos del Metabolismo de los Aminoácidos/terapia , Glutaratos/sangre , Diagnóstico Precoz , Femenino , Humanos , Recién Nacido , Masculino , Pronóstico
7.
Med Biol Eng Comput ; 45(6): 541-51, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17534680

RESUMEN

The surface electroenterogram (EEnG) is a non-invasive method of studying myoelectrical bowel activity. However, surface EEnG recordings are contaminated by cardiac activity, respiratory and motion artifacts, and other sources of interference. The aim of this work is to remove the respiration artifact and the very low frequency components from surface EEnG by means of empirical mode decomposition (EMD). Eleven recording sessions were carried out on canine model. Several parameters were calculated before and after the application of the method: signal-to-interference ratio (S/I ratio) and the attenuation level of the signal and of interference. The results show that the S/I ratio was significantly higher after the application of the method (3.68+/-5.54 dB vs. 10.45+/-3.65 dB), the attenuation level of signal and of interference is -0.49+/-0.80 dB versus -7.26+/-5.42 dB, respectively. Therefore, EMD could be a useful aid in identifying the intestinal slow wave and in removing interferences from EEnG recordings.


Asunto(s)
Electromiografía/métodos , Motilidad Gastrointestinal/fisiología , Algoritmos , Animales , Artefactos , Perros , Intestinos/fisiología , Modelos Biológicos , Procesamiento de Señales Asistido por Computador
8.
Nefrologia ; 27(2): 202-8, 2007.
Artículo en Español | MEDLINE | ID: mdl-17564566

RESUMEN

Cytomegalovirus (CMV) is a pathogen, commonly found in the donors and recipients of solid organ transplantation. CMV is one of the major causes of morbidity and mortality in these patients. Relapsing episodes of CMV infection occur in 23-33% of transplant patients which is likely a reflection of incomplete suppression of viral replication following antiviral treatment with intravenous ganciclovir. We have studied CMV DNA load and antigenemia as markers for relapse of CMV infection in 49 renal transplant patients out of 68 with CMV infection who received a course of intravenous ganciclovir among 300 transplants carried out between January of 2001 and June of 2005. Viral load and antigenemia were measured in blood samples obtained before, during and at the completion of treatment. We also studied different viral load as predictors of relapse CMV infection. Twelve (24.5%) of 49 recipients developed relapsing CMV infection. The relapsing group had higher viral loads after treatment than the no relapsing group. There was no difference in antigenemia level between both groups. The viral loads before and during the treatment, the age and sex of donors and recipients, inmunosupresión, percentage of seronegative recipients with seropositive donors, duration of the therapy and the percentage of patients with heavy immunosuppression were similar in the two groups, but the incidence of acute rejection was higher in the relapsing group. We also evaluated the range of viral load after treatment which is able to trigger the relapse of CMV infection. We conclude that CMV DNA load after treatment is a useful marker for individualizing antiviral treatment of CMV infection in renal transplant recipients. Acute rejection is a risk factor to the relapsing CMV infection.


Asunto(s)
Antígenos Virales/sangre , Infecciones por Citomegalovirus/sangre , Infecciones por Citomegalovirus/virología , Citomegalovirus/inmunología , Trasplante de Riñón/efectos adversos , Carga Viral , Biomarcadores/sangre , Infecciones por Citomegalovirus/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Recurrencia
9.
Homo ; 58(4): 297-307, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17675006

RESUMEN

This paper reports a palaeodietary investigation of the human remains found in the collective Bronze Age burial cave from Vall d'Uixó (Castelló, Spain). Dental pathology, tooth wear as well as buccal dental microwear were analysed. Percentages of dental pathologies were compared with Chalcolithic and Bronze Age sites from the same territory. Dental caries, ante-mortem tooth loss, periodontal disease and abscess frequencies indicate a diet rich in carbohydrate foods. However, dental calculus percentages and macroscopic wear patterns suggest a diet not exclusively relying on agricultural resources. In addition, buccal dental microwear density and length by orientation recorded on micrographs using a scanning electron microscope showed inter-group differences with regard to carnivorous hunter-gatherers and farming populations related to the amount of abrasives in the diet that could correspond to a different dependence on agricultural resources or food preparation technology.


Asunto(s)
Oclusión Dental , Dieta/historia , Paleodontología/métodos , Diente/patología , Caries Dental/patología , Carbohidratos de la Dieta , Grano Comestible , Femenino , Historia Antigua , Humanos , Masculino , Carne , España , Pérdida de Diente/patología
10.
An Pediatr (Barc) ; 67(4): 337-43, 2007 Oct.
Artículo en Español | MEDLINE | ID: mdl-17949643

RESUMEN

INTRODUCTION: Maple syrup urine disease (MSUD) is a rare autosomal recessive disorder caused by an inherited deficiency of branched chain alpha-ketoacid dehydrogenase activity. Accumulation of the amino acids leucine, isoleucine, valine and alloisoleucine and their metabolic products in cells and biological fluids results in severe brain dysfunction. PATIENTS AND METHODS: We present three cases of MSUD diagnosed in Galicia since 2000, the year in which the Extended Newborn Screening Program by tandem mass spectrometry was started in this region. One of the patients was diagnosed on the basis of early clinical presentation and the others by neonatal screening. Enzymatic and molecular studies confirmed two classic cases of MSUD and an intermediate variant. We describe the clinical and biochemical details at confirmation of diagnosis and the long-term outcome of the three patients. Throughout follow-up, all the patients maintained adequate leucine levels, which were near the normal range (mean levels: 220, 177 and 252 micromol/L, respectively). Several moderate metabolic decompensations were observed but leucine levels only occasionally exceeded 1000 micromol/L (one day in two patients). IQ tests were performed in all patients and scores were within the normal range. In view of our results, we believe the following measures are essential to improve the prognosis of MSUD: inclusion of this disease in Expanded Neonatal Screening Programs with early samples (at 2-3 days of life); aggressive treatment in the initial phase and during acute decompensations; strict metabolic control to prevent crises, monitoring of branched-chain amino acids (dried blood spot sample), and maintenance of long term plasma leucine levels below 300 micromol/L.


Asunto(s)
Enfermedad de la Orina de Jarabe de Arce/dietoterapia , Enfermedad de la Orina de Jarabe de Arce/diagnóstico , Antropometría , Áreas de Influencia de Salud , Humanos , Recién Nacido , Enfermedad de la Orina de Jarabe de Arce/epidemiología , España/epidemiología , Espectrometría de Masas en Tándem
11.
Histol Histopathol ; 32(12): 1351-1358, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28585678

RESUMEN

The endocannabinoids are cannabinoids synthesized by mammalian tissues. These compounds are closely related to the regulation of the male reproductive system. However, little is known about the effects produced by 2-arachidonoylglycerol (2AG) on in vitro human sperm functions. This study was undertaken to determine the effects produced by 2AG on fresh human sperm and in the capacitation technique. Semen samples from healthy young men were exposed to different concentrations of 2AG before and during capacitation technique. In this work, we have demonstrated that 2AG induces the spontaneous acrosome reaction and reduces progressive motility in fresh human sperm. During the capacitation technique, sperm becomes more sensitive to low concentrations of 2AG, triggering the acrosome reaction and inhibiting protein phosphorylation. In summary, 2AG affects the in vitro functionality of human sperm by reducing motility, inhibiting capacitation and triggering the acrosome reaction.


Asunto(s)
Reacción Acrosómica/efectos de los fármacos , Ácidos Araquidónicos/toxicidad , Endocannabinoides/toxicidad , Glicéridos/toxicidad , Motilidad Espermática/efectos de los fármacos , Espermatozoides/efectos de los fármacos , Adolescente , Adulto , Humanos , Masculino , Adulto Joven
12.
Nefrologia ; 26(5): 619-22, 2006.
Artículo en Español | MEDLINE | ID: mdl-17117907

RESUMEN

We report the case of a renal transplant recipient who developed acute acalculous cholecyscitis resulting in gallbladder perforation. At admission CMV antigenemia was negative. Emergency laparatomy was performed and showed the gallbladder to be infarted with a perforation. The abdominal cavity contained two litres of sterile bilious fluid. The pathological report showed frequent endothelial cells contained intranuclear and intracitoplasmatic inclusion (fig. 1). Treatment with Ganciclovir iv was started after diagnosis, but a computerized tomography scan demonstrated severe acute pancreatitis (grade E. Baltazar). The patient developed multiorgan failure and died on 19th day after surgery. Necropsy showed cytomegalic inclusions in pancreas (fig. 2), gastrointerstinal tract, lung and graft. A necroticing pneumonia with Mycotic spores and hiphae was seen. Aspergillus was also observed in myocardium (fig. 3).


Asunto(s)
Colecistitis Alitiásica/complicaciones , Infecciones por Citomegalovirus/complicaciones , Trasplante de Riñón , Pancreatitis/complicaciones , Colecistitis Alitiásica/virología , Aspergilosis/complicaciones , Infecciones por Citomegalovirus/diagnóstico , Resultado Fatal , Vesícula Biliar , Cardiopatías/complicaciones , Cardiopatías/microbiología , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia Multiorgánica , Pancreatitis/virología , Rotura Espontánea
13.
Scanning ; 27(1): 23-9, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15712754

RESUMEN

Dental microwear, usually analyzed using scanning electron microscopy (SEM) techniques, is a good indicator of the abrasive potential of past human population diets. Scanning electron microscopy secondary electrons provide excellent images of dental enamel relief for characterizing striation density, average length, and orientation. However, methodological standardization is required for interobserver comparisons since semiautomatic counting procedures are still used for micrograph characterization. The analysis of normally distributed variables allows the characterization of small interpopulation differences. However, the interobserver error rates associated with SEM experience and the degree of expertise in measuring striations are critical to population dietary interpretation. The interobserver comparisons made here clearly indicate that the precision of SEM buccal microwear measurements depends heavily on variable definition and the researcher's expertise. Moreover, error rates are not the only concern for dental microwear research. Low error rates do not guarantee that all researchers are measuring the same magnitudes of the variables considered. The results obtained show that researchers tend to maintain high intrapopulation homogeneity and low measurement error rates, whereas significant interobserver differences appear. Such differences are due to a differential interpretation of SEM microwear features and variable definitions that require detailed and precise agreement among researchers. The substitution of semiautomatic with fully automated procedures will completely avoid interobserver error rate differences.


Asunto(s)
Esmalte Dental/ultraestructura , Variaciones Dependientes del Observador , Paleodontología/métodos , Abrasión de los Dientes/patología , Animales , Dieta , Fósiles , Hominidae , Humanos , Microscopía Electrónica de Rastreo/métodos , Paleodontología/normas , Papio anubis
14.
J Comp Neurol ; 356(4): 491-504, 1995 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-7560262

RESUMEN

Substance P (SP) is a neuropeptide that acts as a neurotransmitter or a neuromodulator in the retina. The aim of this study was to identify the type(s) and the distribution of the SP-immunoreactive (SP-IR) cells in the human retina. We have used an antiserum to SP to immunostain neurons in postmortem human retinae. Immunostained retinae were processed with the avidin-biotin complex (ABC) to visualize the cells either whole mounted in glycerol or embedded in plastic. Some retinae were also sectioned at 20 microns in order to obtain radial views of stained cells. SP-IR amacrine cells stain intensely and appear to be of a single type in the human retina. They are large-field cells with large cell bodies (16 microns diameter) lying in normal or displaced positions on either side of the inner plexiform layer (IPL). Their sturdy, spiny, and appendage-bearing dendrites stratify in stratum 3 (S3) of the IPL, where many overlapping, fine dendrites intermingle to form a plexus of stained processes. Either cell bodies or primary dendrites emit an "axon-like" process that, typically, divides into two long, fine processes, which run in opposite directions for hundreds of micrometers in S5 and S3 before disappearing as distinct entities in the stained plexus in S3. Long, fine dendrites also pass from the dendritic plexus to run in S5 and down to the nerve fiber layer to end as large varicosities at blood vessel walls. In addition, fine processes are emitted from the dendritic plexus that runs in S1, and some pass up to the outer plexiform layer (OPL) to run therein for short distances. The SP-IR amacrine cell has many similarities to the thorny, type 2 amacrine cells described from Golgi studies. In addition to the SP-IR amacrine cells, a presumed ganglion cell type is faintly immunoreactive. Its 20-22 microns cell body gives rise to a radiate, sparsely branched, wide-spreading dendritic tree running in S3. Its dendrites and cell body become enveloped by the more intensely SP-IR processes and boutons from the SP-IR amacrine cell type. The SP-IR ganglion cell type most resembles G21 from a Golgi study.


Asunto(s)
Neuronas Aferentes/química , Retina/citología , Células Ganglionares de la Retina/química , Sustancia P/inmunología , Recuento de Células , Tamaño de la Célula , Dendritas/química , Dendritas/ultraestructura , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Neuronas Aferentes/ultraestructura , Retina/química , Células Ganglionares de la Retina/ultraestructura , Sustancia P/análisis
15.
J Comp Neurol ; 263(4): 613-7, 1987 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-3667992

RESUMEN

In this paper the postnatal changes in the cytoskeleton of the rat optic nerve fibers are described and quantified. These changes are also compared with other parameters such as myelination and axonal caliber with the aim of describing a general pattern of optic nerve maturation from a morphological point of view. The results showed that during the first postnatal week microtubules outnumbered neurofilaments but between days 8 and 20 the neurofilaments rapidly increased and on day 20 were about twice as numerous as microtubules. This proportion remained almost unaltered from the end of the third week to the 44th postnatal day. The comparison with other parameters suggested that the cytoskeleton, and in particular the proportion between its components, may be a more reliable index for measuring optic nerve maturation than other variables commonly used.


Asunto(s)
Animales Recién Nacidos/crecimiento & desarrollo , Citoesqueleto/fisiología , Filamentos Intermedios/fisiología , Microtúbulos/fisiología , Nervio Óptico/crecimiento & desarrollo , Ratas/crecimiento & desarrollo , Animales , Axones/fisiología , Vaina de Mielina/fisiología , Nervio Óptico/anatomía & histología , Nervio Óptico/fisiología , Ratas Endogámicas
16.
J Comp Neurol ; 420(4): 512-26, 2000 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-10805924

RESUMEN

Acetylcholine has important epigenetic roles in the developing retina. In this study, cells that expressed choline acetyltransferase (ChAT), the enzyme that synthesizes acetylcholine, were investigated in embryonic, postnatal, and adult turtle retinas by using immunofluorescence histochemistry. ChAT was present at stage 15 (S15) in cells near the vitreal surface. With the formation of the inner plexiform layer (IPL) at S18, ChAT-immunoreactive (-IR) cells were located in the inner nuclear layer (INL) and the ganglion cell layer (GCL). In the INL, presumed starburst amacrine cells were homogenous in appearance and formed a single row next to the IPL: This pattern was conserved until adulthood. In the GCL, however, there were multiple rows of ChAT-IR cells early in development, and this high density of labeled cells continued during the embryonic stages, until around birth. The high density of ChAT-IR cells in the GCL was due in part to a population of cells that expressed ChAT transiently. In postnatal stages and adult retinas, the presumed starburst amacrine ChAT-IR cells formed two mirror-like rows of homogenous cells on both borders of the IPL. Two cholinergic dendritic strata that were continuous with these cells were observed as early as S18, and their depths in the IPL were relatively stable throughout development. A third population of ChAT-IR cells was observed toward the middle of the INL around S25 and persisted into adulthood. Finally, cells in the outer nuclear layer (ONL) were ChAT-IR during the embryonic stages, were less immunoreactive during the postnatal stages, and were not immunoreactive in the adult retinas.


Asunto(s)
Colina O-Acetiltransferasa/metabolismo , Retina/embriología , Retina/crecimiento & desarrollo , Tortugas/crecimiento & desarrollo , Animales , Colina O-Acetiltransferasa/análisis , Dendritas/fisiología , Dendritas/ultraestructura , Inmunohistoquímica , Morfogénesis , Retina/enzimología , Tortugas/embriología
17.
Histol Histopathol ; 14(4): 1053-65, 1999 10.
Artículo en Inglés | MEDLINE | ID: mdl-10506921

RESUMEN

The structure of light- and dark-adapted retina of the black bass, Micropterus salmoides has been studied by light and electron microscopy. This retina lacks blood vessels at all levels. The optic fiber layer is divided into fascicles by the processes of Müller cells and the ganglion cell layer is represented by a single row of voluminous cells. The inner nuclear layer consists of two layers of horizontal cells and bipolar, amacrine and interplexiform cells. In the outer plexiform layer we observed the synaptic terminals of photoreceptor cells, rod spherules and cone pedicles and terminal processes of bipolar and horizontal cells. The spherules have a single synaptic ribbon and the pedicles possess multiple synaptic ribbons. Morphologically, we have identified three types of photoreceptors: rods, single cones and equal double cones which undergo retinomotor movements in response to changes in light conditions. The cones are arranged in a square mosaic whereas the rods are dispersed between the cones.


Asunto(s)
Lubina/anatomía & histología , Retina/ultraestructura , Animales , Oscuridad , Luz , Células Fotorreceptoras Retinianas Conos/ultraestructura , Células Fotorreceptoras Retinianas Bastones/ultraestructura
18.
Histol Histopathol ; 17(3): 721-9, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12168780

RESUMEN

Terminal dendrites of cone horizontal cells (HCs) in teleost retinas show numerous spine-like protrusions named spinules, which are invaginated into the cone pedicles during light-adaptation, but retracted during dark-adaptation. Somata of HC show nematosomes whose size decreases as the number of spinules increases. Mechanisms regulating these changes in nematosomes and spinules are only partially understood, being an area of controversy in retinal cell biology. It has been suggested that efferent fibres from the brain to the retina might be involved in the control of spinule formation. Moreover, we have reported that actin depolymerization has an interocular effect on spinule formation, which could be mediated by these fibres. In the present report, we show an interocular effect on spinule dynamics: the monocular intravitreal injection of dopamine (DA) and 6-hydroxydopamine (6-OHDA), two drugs that affect the spinule formation, produces the same effects in the contralateral, untreated eye as in the injected eye. Our results reinforce the idea of an interocular central control of this phenomenon of synaptic plasticity. Dopamine-dependent events in the retina appear to be necessary to forge the afferent signals eliciting this interocular effect.


Asunto(s)
Dopamina/farmacología , Oxidopamina/farmacología , Retina/efectos de los fármacos , Cuerpo Vítreo/efectos de la radiación , Adrenérgicos/farmacología , Animales , Lubina , Inmunohistoquímica , Luz , Microscopía Electrónica , Retina/ultraestructura
19.
Neuroreport ; 5(3): 365-7, 1993 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-8298106

RESUMEN

The size of any axon is generally related to an internal programme (probably common for all neurones) that determines the number and organization of its cytoskeletal components. Here we show that axons from visually deprived rats are smaller than controls, although the number of microtubules and neurofilaments remains unchanged. Moreover the distance between both microtubules and neurofilaments and the amounts of 200 kDa, 160 kDa and 68 kDa neurofilament proteins are also diminished in the deprived axons. We suggest that cytoskeletal organization and axonal calibre are not only determined by intrinsic (genomic) factors, but that environmental stimulation is important for normal growth of nerve cells.


Asunto(s)
Axones/fisiología , Nervio Óptico/crecimiento & desarrollo , Visión Ocular/fisiología , Animales , Axones/ultraestructura , Western Blotting , Proteínas del Citoesqueleto/metabolismo , Inmunohistoquímica , Microtúbulos/metabolismo , Fibras Nerviosas/fisiología , Proteínas de Neurofilamentos/biosíntesis , Nervio Óptico/citología , Ratas , Ratas Wistar , Visión Monocular
20.
J Neurosci Methods ; 50(1): 1-15, 1993 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8277777

RESUMEN

The pattern of distribution of a population of cells is of considerable interest to biologists and neurobiologists. However, the labor involved in collecting and analyzing the data often requires a significant amount of time. This paper presents a compiled BASIC program written using the Microsoft QuickBasic compiler for Apple Macintosh to facilitate such studies. The program allows collection and analysis of data that can be introduced either with the aid of a digitizing tablet of directly imported as x,y coordinates from different sources as, for example, word processors or image analysis software. Subsequently the program provides a quick, easy and interactive way of access to statistical, mathematical and graphical techniques used in the analysis of spatial point patterns. These techniques include several measures of dispersion (quadrat count, nearest neighbor and a 2-dimensional point autocorrelogram analysis) and arrangement. Although the program has been tested on spatial organization of retinal cells, it can be used to study the distribution of other cells in the nervous system and for different projects, as for example the distribution of microtubules and neurofilaments inside the axons. This software is available from the authors.


Asunto(s)
Retina/citología , Programas Informáticos , Animales , Modelos Neurológicos , Tortugas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA