RESUMEN
Bovine meningoencephalitis caused by BHV-5, a double-stranded DNA enveloped virus that belongs to the family Herpesviridae and subfamily Alphaherpesvirinae, is an important differential diagnosis of central nervous diseases. The aim of this study was to describe the histological changes in the central nervous system of calves experimentally infected with BHV-5 and compare these changes with the PCR and IHC results. Formalin-fixed paraffin-embedded central nervous system samples from calves previously inoculated with BHV-5 were microscopically evaluated and tested using IHC and PCR. All the animals presented with nonsuppurative meningoencephalitis. From 18 evaluated areas of each calf, 32.41% and 35.19% were positive by IHC and PCR, respectively. The telencephalon presented more accentuated lesions and positive areas in the PCR than other encephalic areas and was the best sampling area for diagnostic purposes. Positive areas in the IHC and PCR were more injured than IHC and PCR negative areas. The animal with neurological signs showed more PCR- and IHC-positive areas than the other animals.(AU)
A meningoencefalite bovina causada pelo BHV-5, um vírus DNA fita dupla envelopado que pertence à família Herpesviridae e subfamília Alphaherpesvirinae, é um importante diagnóstico diferencial das doenças do sistema nervoso central. O objetivo deste estudo foi descrever as alterações histológicas no sistema nervoso central de bovinos experimentalmente infectados com BHV-5 e comparar estas alterações com os resultados de imunoistoquímica (IHQ) e PCR. Amostras do sistema nervoso central de bezerros previamente inoculados com BHV-5 foram microscopicamente avaliadas e submetidas à IHQ e PCR. Todos os animais apresentaram meningoencefalite não-supurativa. Das 18 áreas avaliadas de cada bezerro, 32,41% e 35,13% foram positivas na IHQ e PCR, respectivamente. O telencéfalo apresentou lesões mais acentuadas e foi mais positivo na PCR do que as demais áreas encefálicas e se apresentou como a melhor área para coleta de material para o diagnóstico. As áreas positivas na IHQ e na PCR apresentaram lesões mais acentuadas do que as áreas negativas para as mesmas técnicas. O animal com sinais neurológicos apresentou mais áreas positivas para PCR e IHQ do que os demais animais.(AU)
Asunto(s)
Animales , Bovinos , Sistema Nervioso Central/anatomía & histología , Sistema Nervioso Central/química , Sistema Nervioso Central/inmunología , Sistema Nervioso Central/patología , MeningoencefalitisRESUMEN
El objetivo fue demostrar que los llamados meduloblastomas del Sistema Nervioso Central son neuroblastomas, tumores de origen neural con identidad propia. Siguiendo a Del Río Hortega y Polak se estudiaron 33 meduloblastomas cerebelares clínica y anatomopatológicamente demostrados. Se utilizaron técnicas de anilinas, impregnación argéntica y de inmunohistoquímica. Se analizó extensamente la bibliografía haciendo énfasis en el origen e histogénesis de las neuronas. Se tuvo en cuenta un principio básico que para reconocerlas se debe teñir el núcleo, el citoplasma y sus prolongaciones. Con las técnicas habituales de hematoxilina- eosina se observa sólo el núcleo y citoplasma, con la inmunohistoquímica se caracteriza la estirpe y con las técnicas argénticas las prolongaciones, con las que Cajal, Del Río Hortega, Golgi y otros estudiaron y descubrieron las células del SNC normal y patológico, cuya teoría de la neurona de Cajal no fue superada hasta la actualidad.
SUMMARY: The purpose of this study was to demonstrate that the called meduloblastoma of the central nervous system, are neuroblastomas, tumors of neural origin with its own identity .Following the published studies from Del Rio Hortega and Pollak, we studied 33 cerebellar medulloblastoma, clinically and pathologically demonstrated We used silver, aniline stains and immunohistochemestry. A comprehensive literature review was conducted, with emphasis on the origin and histogenesis of neurons. A basic principle was considered to recognize a neuron, the nucleus, the cytoplasm and the neuronal extensions must be stained. With standard hematoxilin and eosin techniques we only observed the nucleus and the cytoplasm. The immunohistochemestry showed the cell line origin and the silver stain make evident the neuronal extensions. Del Rio Hortega, Cajal, Golgi and others discovered and studied the normal and pathological central nervous system cell. The Cajals neuron theory was unsurpassed even today.
Asunto(s)
Humanos , Masculino , Femenino , Técnicas de Diagnóstico Neurológico , Inmunohistoquímica/métodos , Neuroblastoma/inmunología , Sistema Nervioso Central/química , ArgentinaRESUMEN
BACKGROUND: Brain tumors are one of the leading cancers worldwide; in the National Institute of Neurology and Neurosurgery (INNN) these tumors are the leading cause of morbitity and mortality. OBJECTIVE: Standardize biopsies, colletion, processing and storage biologic material of molecular studies. METHODS: with a previously signed surgical consent, a tumor and blood biopsy was done to 134 patients. Their DNA was extracted and a database was filled considering technical, ethical and legal aspects. In order to have optimal biologic material the procedure was standardized between the surgical and research laboratory teams. RESULTS: The biopsy, transportation, processing and storage were standardized. 134 patients were included (67 male and 67 female) with an average age of 46.28 years (range 15-81). The most frequently biopsied tumor was the meningioma (42%). The integrity of the obtained material was determined by agarose gel electrophoretic analysis. CONCLUSION: the INNN biobank has a standardized system that biopsies, processes and stores optimum quality biologic material that will be the basis of future molecular studies.
Asunto(s)
Bancos de Muestras Biológicas/normas , Neoplasias del Sistema Nervioso Central/patología , ADN de Neoplasias , Meningioma/patología , Neoplasias Neuroepiteliales/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Bancos de Muestras Biológicas/organización & administración , Biopsia/normas , Sistema Nervioso Central/química , Sistema Nervioso Central/patología , Neoplasias del Sistema Nervioso Central/química , Neoplasias del Sistema Nervioso Central/genética , Neoplasias del Sistema Nervioso Central/secundario , Neoplasias de los Nervios Craneales/química , Neoplasias de los Nervios Craneales/genética , Neoplasias de los Nervios Craneales/patología , ADN de Neoplasias/análisis , ADN de Neoplasias/genética , ADN de Neoplasias/aislamiento & purificación , Bases de Datos Factuales , Electroforesis en Gel de Agar , Femenino , Humanos , Masculino , Meningioma/química , Meningioma/genética , México , Persona de Mediana Edad , Neoplasias Neuroepiteliales/química , Neoplasias Neuroepiteliales/genética , Neoplasias del Sistema Nervioso Periférico/química , Neoplasias del Sistema Nervioso Periférico/genética , Neoplasias del Sistema Nervioso Periférico/patología , Preservación Biológica/métodos , Preservación Biológica/normas , Garantía de la Calidad de Atención de Salud , Manejo de Especímenes/normas , Nervios Espinales/química , Nervios Espinales/patología , Transportes/normas , Adulto JovenRESUMEN
Drugs acting on the central nervous system (CNS) have to cross the blood-brain barrier (BBB) in order to perform their pharmacological actions. Passive BBB diffusion can be partially expressed by the blood/brain partition coefficient (logBB). As the experimental evaluation of logBB is time and cost consuming, theoretical methods such as quantitative structure-property relationships (QSPR) can be useful to predict logBB values. In this study, a 2D-QSPR approach was applied to a set of 28 drugs acting on the CNS, using the logBB property as biological data. The best QSPR model [n = 21, r = 0.94 (r² = 0.88), s = 0.28, and Q² = 0.82] presented three molecular descriptors: calculated n-octanol/water partition coefficient (ClogP), polar surface area (PSA), and polarizability (α). Six out of the seven compounds from the test set were well predicted, which corresponds to good external predictability (85.7%). These findings can be helpful to guide future approaches regarding those molecular descriptors which must be considered for estimating the logBB property, and also for predicting the BBB crossing ability for molecules structurally related to the investigated set.
Fármacos que atuam no sistema nervoso central (SNC) devem atravessar a barreira hematoencefálica (BHE) para exercerem suas ações farmacológicas. A difusão passiva através da BHE pode ser parcialmente expressa pelo coeficiente de partição entre os compartimentos encefálico e sanguíneo (logBB, brain/blood partition coefficient). Considerando-se que a avaliação experimental de logBB é dispendiosa e demorada, métodos teóricos como estudos das relações entre estrutura química e propriedade (QSPR, Quantitative Structure-Property Relationships) podem ser utilizados na previsão dos valores de logBB. Neste estudo, uma abordagem de QSPR-2D foi aplicada a um conjunto de 28 moléculas com ação central, usando logBB como propriedade biológica. O melhor modelo de QSPR [n = 21, r = 0,94 (r² = 0,88), s = 0,28 e Q² = 0,82] apresentou três descritores moleculares: o coeficiente calculado de partição n-octanol/água (ClogP), área de superfície polar (PSA) e polarizabilidade (α). Seis dos sete compostos do conjunto de avaliação foram bem previstos pelo modelo, o que corresponde a um bom poder de previsão externa (85,7%). Os resultados obtidos podem auxiliar de forma relevante em estudos futuros, orientando quais descritores moleculares devem ser considerados para estimar logBB e prever a passagem através da BHE de moléculas estruturalmente relacionadas às do conjunto investigado.
Asunto(s)
Barrera Hematoencefálica , Barrera Hematoencefálica/química , Sistema Nervioso Central/química , Benzodiazepinas/análisis , Relación Estructura-Actividad CuantitativaRESUMEN
The distribution of cholecystokinin-like immunoreactivity was studied in the central nervous system of the heteropteran insect Triatoma infestans using high-sensitivity immunocytochemistry. In the protocerebrum, CCK-IR somata were observed in the anteromedial, anterolateral and posterior cell-body layers. The neuropils displayed different densities of immunoreactive neurites. Few immunoreactive somata were found in the optic lobe in both the medial and lateral soma rinds, as well as in the proximal optic lobe. Immunoreactive fibers were present in the medulla and lobula neuropils. The sensory deutocerebrum contained a higher number of immunopositive perikarya than the antennal mechanosensory and motor center. The antennal lobe glomeruli displayed a moderate density of immunoreactive fibers. With regard to the subesophageal ganglion, numerous CCK-IR somata were found close to the root of the mandibular nerve; others were present in the soma rind of the remaining neuromeres. CCK-IR perikarya were present in both thoracic ganglia, with the abdominal neuromeres containing the highest number of positive somata. The neuropils of both ganglia showed moderate densities of immunopositive processes. The distribution of CCK-LI in somata and neuropils of central nervous system of T. infestans is widespread suggesting that a CCK-like peptide may act mainly as a neuromodulator in the integration of information from distinct sensory receptors.
Asunto(s)
Sistema Nervioso Central/química , Colecistoquinina/análisis , Triatoma/química , Animales , Sistema Nervioso Central/inmunología , Colecistoquinina/inmunología , Ganglios de Invertebrados/metabolismo , Inmunohistoquímica , Triatoma/citologíaRESUMEN
The urocortin (UCN)-like immunoreactivity and UCN mRNA distribution in various regions of the nonprimate mammalian brain have been reported. However, the Edinger-Westphal nucleus (EW) appears to be the only brain site where UCN expression is conserved across species. Although UCN peptides are present throughout vertebrate phylogeny, the functional roles of both UCN and EW remain poorly understood. Therefore, a study focused on UCN system organization in the primate brain is warranted. By using immunohistochemistry (single and double labeling) and in situ hybridization, we have characterized the organization of UCN-expressing cells and fibers in the central nervous system and pituitary of the capuchin monkey (Cebus apella). In addition, the sequence of the prepro-UCN was determined to establish the level of structural conservation relative to the human sequence. To understand the relationship of acetylcholine cells in the EW, a colocalization study comparing choline acetyltransferase (ChAT) and UCN was also performed. The cloned monkey prepro-UCN is 95% identical to the human preprohormone across the matched sequences. By using an antiserum raised against rat UCN and a probe generated from human cDNA, we found that the EW is the dominant site for UCN expression, although UCN mRNA is also expressed in spinal cord lamina IX. Labeled axons and terminals were distributed diffusely throughout many brain regions and along the length of the spinal cord. Of particular interest were UCN-immunoreactive inputs to the medial preoptic area, the paraventricular nucleus of the hypothalamus, the oral part of the spinal trigeminal nucleus, the flocculus of the cerebellum, and the spinal cord laminae VII and X. We found no UCN hybridization signal in the pituitary. In addition, we observed no colocalization between ChAT and UCN in EW neurons. Our results support the hypothesis that the UCN system might participate in the control of autonomic, endocrine, and sensorimotor functions in primates.
Asunto(s)
Cebus/metabolismo , Sistema Nervioso Central/química , Hormona Liberadora de Corticotropina/análisis , Hormona Liberadora de Corticotropina/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Cebus/genética , Inmunohistoquímica , Hibridación in Situ , Masculino , Datos de Secuencia Molecular , Vías Nerviosas/química , UrocortinasRESUMEN
The distributions of neuropeptide Y (NPY) -like immunoreactivity (LI) and that of its Y1 receptor (Y1), as well as their coexistence with cholecystokinin (CCK) -LI, were studied in the central nervous system of Triatoma infestans by using immunohistochemistry. NPY-immunoreactive (IR) cell bodies and fibers were observed in the brain, subesophageal ganglion, and thoracic ganglia. NPY-IR somata were seen in the optic lobe and the anteromedial and caudolateral soma rinds of the protocerebrum. Immunostained cell bodies were also found in the lateral edge of the antennal lobe glomeruli as well as in the caudal part of the antennal mechanosensory and motor center. The subesophageal ganglion harbored few NPY-IR perikarya and fibers in the three neuromeres. Positive somata of the prothoracic ganglion were detected near both the cephalic and posterior connectives as well as by the root of prothoracic nerve I, whereas in the posterior ganglion, they were seen by the roots of mesothoracic and abdominal nerves. Coexpression of NPY-LI and CCK-LI was seen in cell bodies of the protocerebrum, the subesophageal and posterior ganglia. Protocerebral Y1-IR cell groups were detected in the anterolateral and posteromedial soma rinds and at the level of the lamina ganglionaris and the external optic chiasma. Numerous positive perikarya surrounded the antennal lobe glomeruli as well as the antennal mechanosensory and motor center. Other immunostained cell bodies were seen in the posterior edge of the esophageal canal and by the roots of the mandibular and the maxillary nerves. Y1-IR cell bodies of the prothoracic ganglion were found near the roots of prothoracic nerves I-II, whereas in the posterior ganglion, they were located mainly in the abdominal neuromeres. Coexpression of Y1-LI and CCK-LI were detected in several brain areas as well as in the metathoracic and abdominal neuromeres of the posterior ganglion. When assessed by immunoblotting, Y1 antibodies detected two protein bands between 34 and 46 kDa. Analysis of the distribution patterns of NPY-LI and Y1-LI suggest that peptide and receptor are mainly involved in the processing of information coming from sensory receptors.
Asunto(s)
Neuropéptido Y/análisis , Receptores de Neuropéptido Y/análisis , Triatoma/química , Animales , Sistema Nervioso Central/química , Inmunohistoquímica , MasculinoRESUMEN
We have used passive transfer of myelin-reactive lymphocytes in the Wistar rat model of experimental autoimmune encephalomyelitis (EAE) to investigate the nature of the central nervous system immunopathological alterations induced by these cells. Mononuclear cells from lymph nodes or spleen from sick myelin/complete Freund's adjuvant-immunized donors did not transfer clinical disease. However, depending on the previous treatment of the transferred cells, recipients develop central nervous system biochemical and histological alterations. Fresh cells from lymph nodes immediately transferred after procurement from the sick EAE donor rat were capable of inducing the most significant diminution in the content of myelin basic protein, sulfatides, and 2',3'-cyclic nucleotide-3'-phosphohydrolase activity, with concomitant inflammatory infiltrations of white matter, principally in spinal cord and cerebellar lobules. Similar alterations were observed when animals were injected with spleen mononuclear cells activated in the presence of a nonspecific mitogen as concanavalin A. However, antigen-specific activated spleen cells generated by culturing in the presence of bovine myelin induced alterations to a lesser degree. Results point to a dissociation of the clinical disease from the central nervous system biochemical and histopathological lesions occurring in the EAE-transferred Wistar rats and indicate that these alterations in EAE are induced principally by T cells activated in vivo rather than by cells activated in vitro by myelin antigens. Therefore, these findings suggest a possible participation of lymphocytes unlike the encephalitogenic T cells in the induction of the described alterations and provide a useful model to explore further the subclinical responses to this experimental disease.
Asunto(s)
Sistema Nervioso Central/química , Encefalomielitis Autoinmune Experimental/inmunología , Proteína Básica de Mielina/inmunología , Linfocitos T/trasplante , 2',3'-Nucleótido Cíclico Fosfodiesterasas/análisis , Animales , Autoanticuerpos/sangre , Bovinos , Células Cultivadas , Sistema Nervioso Central/inmunología , Concanavalina A , Encefalomielitis Autoinmune Experimental/metabolismo , Encefalomielitis Autoinmune Experimental/fisiopatología , Femenino , Masculino , Proteína Básica de Mielina/farmacología , Vaina de Mielina/enzimología , Vaina de Mielina/inmunología , Ratas , Ratas Wistar , Linfocitos T/citología , Linfocitos T/enzimologíaRESUMEN
Fibronectin (FN), a large family of plasma and extracellular matrix (ECM) glycoproteins, plays an important role in leukocyte migration. In normal central nervous system (CNS), a fine and delicate mesh of FN is virtually restricted to the basal membrane of cerebral blood vessels and to the glial limitans externa. Experimental autoimmune encephalomyelitis (EAE), an inflammatory CNS demyelinating disease, was induced in Lewis rats with a spinal cord homogenate. During the preclinical phase and the onset of the disease, marked immunolabelling was observed on the endothelial luminal surface and basal lamina of spinal cord and brainstem microvasculature. In the paralytic phase, a discrete labelling was evident in blood vessels of spinal cord and brainstem associated or not with an inflammatory infiltrate. Conversely, intense immunolabelling was present in cerebral and cerebellar blood vessels, which were still free from inflammatory cuffs. Shortly after clinical recovery minimal labelling was observed in a few blood vessels. Brainstem and spinal cord returned to normal, but numerous inflammatory foci and demyelination were still evident near the ventricle walls, in the cerebral cortex and in the cerebellum. Intense expression of FN in brain vessels ascending from the spinal cord towards the encephalon preceded the appearance of inflammatory cells but faded away after the establishment of the inflammatory cuff. These results indicate an important role for FN in the pathogenesis of CNS inflammatory demyelinating events occurring during EAE
Asunto(s)
Ratas , Animales , Femenino , Sistema Nervioso Central , Encefalomielitis Autoinmune Experimental/inmunología , Fibronectinas/inmunología , Anticuerpos Monoclonales , Sistema Nervioso Central/química , Sistema Nervioso Central/ultraestructura , Encefalomielitis Autoinmune Experimental/patología , Encefalomielitis/inmunología , Encefalomielitis/patología , Fibronectinas/química , Inmunohistoquímica , Ratas Endogámicas LewRESUMEN
Invertebrate glial cells show a variety of morphologies depending on species and location. They have been classified according to relatively general morphological or functional criteria and also to their location. The present study was carried out to characterize the organization of glial cells and their processes in the zona fasciculata and in the protocerebral tract of the crab Ucides cordatus. We performed routine and cytochemical procedures for electron microscopy analysis. Semithin sections were observed at the light microscope. The Thiéry procedure indicated the presence of carbohydrates, particularly glycogen, in tissue and in cells. To better visualize the axonal ensheathment at the ultrastructural level, we employed a method to enhance the unsaturated fatty acids present in membranes. Our results showed that there are at least two types of glial cells in these nervous structures, a light one and a dark one. Most of the dark cell processes have been mentioned in the literature as extracellular matrix, but since they presented an enveloping membrane, glycogen and mitochondria - intact and with different degrees of disruption - they were considered to be glial cells in the present study. We assume that they correspond to the perineurial cells on the basis of their location. The light cells must correspond to the periaxonal cells. Some characteristics of the axons such as their organization, ensheathment and subcellular structures are also described
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Animales , Sistema Nervioso Central/química , Neuroglía/ultraestructura , Axones/ultraestructura , Braquiuros , Oscuridad , Matriz Extracelular , Luz , Microscopía ElectrónicaRESUMEN
Previamente informamos sobre la liberación inducida por despolarización del aminoácido inhibitorio GABA y del péptido modulador encefalina (bayón y col. 1986). Un hallazgo interesante observado durante el curso de estos experimentos es el hecho de que sustancias de alto peso molecular cuantificadas por el método de Lowry, son liberadas in vivo en condiciones basales y por estimulación despolarizante del tejido nervioso de la rata con K+ 50 mM. Dentro de este contexto, Bayón (1986) observó que la liberación inducida del material protéico con K+ 50 mM en el estriado de la rata, era parcialmente dependiente de la concentración de Ca++ en el líquido de perfusión (1.8 mM), lo que sugería que la secreción neuronal de este material protéico de alto peso molecular, se libera por los mecanismos fisiológicos establecidos de acoplamiento "estimulo-secreción" que se dan para los transmisores peptídicos y para los transmisores no peptídicos. Sin embargo, el origen de este material protéico, liberado bajo estimulación química despolarizante del tejido nervioso, aún queda por elucidarse, puesto que este material pudiera tener un origen plasmático mediante la extravasación de proteínas del compartimiento vascular al espacio interneuronal. Dentro de este contexto exploramos la hipótesis de que este material protéico pudiera tener un origen neuronal exclusivo, mediante la aplicación local de un precursor metabólico, como es el aminoácido S-Metionina al estradio de la rata. Nuestros resultado muestran que sólo una pequeña fracción del material protéico sintetizado in situ y precipitado por TCA, es liberado en condiciones basales y en condiciones de despolarización química del tejido nervioso durante la perfusión in vivo del estriado de la rata. Estos resultados preliminares sugieren, por lo menos, que este material de alto peso molecular liberado al espacio sináptico pudiera ejercer funciones importantes en la comunicación química interneuronal, tal como se ha encontrado en otras especies de alto peso molecular, como la AchE y la dopamina-beta-hidroxilasa(DBH)
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Animales , Ratas , Perfusión , Neurobiología , Sistema Nervioso Central/química , Ratas Sprague-Dawley , Metionina , Estimulación Química , Proteínas del Tejido Nervioso , Proteínas del Tejido Nervioso/síntesis químicaRESUMEN
Relatamos um caso de linfoma näo Hodgkin de grandes células B em gânglios da regiäo cervical e retroperitôneo e com sítios de comprometimento extra nodal: encéfalo, calota craniana, couro cabeludo e infiltraçäo de vértebra T4. O perfil sorológico se mostrou negativo para anticorpos anti-HIV e a paciente foi tratada com seis ciclos de quimioterapia sistêmica de terceira geraçäo para linfomas agressivos (ProMACE-CytaBOM) em doses convencionais e radioterapia em encéfalo (dose total 4.000 cGY).Encontra-se em remissäo clínica e radiológica completa dez meses após o diagnóstico de linfoma. Discutimos o tratamento do linfoma primário de sistema central em pacientes näo imunodeprimidos.
Asunto(s)
Humanos , Femenino , Adulto , Sistema Nervioso Central/química , Linfoma no Hodgkin , Cisplatino/uso terapéutico , Citocinas/uso terapéutico , Metotrexato/uso terapéutico , Procarbazina/uso terapéutico , Radioterapia , TomografíaRESUMEN
N-Acetylsuccinimidylglutamate [(asu)NAAG], a cyclic form of the peptide N-acetylaspartylglutamate (NAAG) in which the aspartyl residue is linked to glutamate via the alpha- and beta-carboxylates, was identified and quantified by HPLC in the murine and bovine CNS. In the rat, the highest concentrations of (asu)NAAG were detected in the spinal cord (1.83 +/- 0.15 pmol/mg of wet tissue weight) and brainstem (1.16 +/- 0.08 pmol/mg wet weight), whereas the levels were below the limit of detection in cerebellum, hippocampus, and cerebral cortex. (Asu)NAAG was also detected in significant amount in the superior colliculus and lateral geniculate nucleus (1.17 +/- 0.05 and 0.82 +/- 0.13 pmol/mg we weight, respectively). Although the tissue content of (asu)NAAG was about three orders of magnitude lower than that of NAAG, levels of both peptides were positively correlated among different CNS regions (r=0.74, p<0.003). In the rat spinal cord, (asu)NAAG levels progressively increased from week 2 to month 12 after birth. In bovine spinal cord, the contents of (asu)NAAG and NAAG were comparable in gray and white matter as well as in the dorsal and ventral horns. These results suggest that NAAG and (asu)-NAAG are closely related metabolically and raise the question of the physiological significance of such a cyclic peptide.
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Sistema Nervioso Central/química , Dipéptidos/análisis , Antagonistas de los Receptores Histamínicos H1/análisis , Envejecimiento/metabolismo , Animales , Química Encefálica , Bovinos , Cromatografía , Dipéptidos/química , Femenino , Antagonistas de los Receptores Histamínicos H1/química , Imidas/análisis , Masculino , Neuropéptidos/análisis , Neuropéptidos/química , Ratas , Ratas Endogámicas , Médula Espinal/químicaRESUMEN
O hormônio concentrador de melanina (MCH) é um heptadecapeptídeo cíclico descrito pela primeira vez em hipófise de salmäo e posteriormente em alguns mamíferos. Os corpos celulares McH-ir encontram-se localizados em regiöes específicas do sistema nervoso central (SNC) do rato, como a Zona Incerta (EI) e a Área Hipotalâmica Lateral (AHL) enquanto que as fibras apresentam-se espalhadas por todo o neuro-eixo. Indica que a inervaçäo cortical é densa e homogênea por todo o neocórtex, assim como, a inervaçäo de várias regiöes da formaçäo reticular, como o núcleo pedunculopontino do tegmento (PPTg). Faz um estudo com múltiplos traçadores neuronais em ratos albinos machos (Wistar) usando 6 procedimentos distintos. Utiliza injeçöes de Diamidino Yellow (DY) no córtex motor (CxM) e de True Blue (TB) no PPTg. Demonstra a existência de neurônios MCH-ir marcados com ambos os traçadores distintamente, tanto na ZI quanto na AHL. Realiza controle com leucoaglutimina do Phaseolus vulgaris (PHA-L) injetado nestes territórios, demonstrando a inervaçäo do CxM e do PPTg originários das regiöes onde as células dupla e triplamente marcada foram encontradas. Conclui que estas células säo também NEI-ir; os resultados envidenciam a presença de colaterais de AHL e ZI para 2 regiöes de SNC envolvidas com o comportamento locomotor. Discute a pesquisa em termos de envolvimento do MCH com o comportamento alimentar, que justamente com o locomotor indica uma atuaçäo na busca do alojamento (a maior quantidade de células marcadas säo originárias de fibras localizadas na regiäo motora das vibrissas), e no sistema reticular ativador ascendente
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Animales , Sistema Nervioso Central/química , Corteza Motora/química , Hormonas Hipotalámicas/análisis , Melaninas/análisis , Ratas WistarRESUMEN
We describe in this work X-ray scattering and electron microscope studies of rat sciatic and optic nerves as a function of temperature. The scattering experiments were analyzed as described in the previous papers of this series: a variety of parameters were determined, some of which characterize the lattice disorder, others the structure of the motif. The main results are the following. All the parameters determined by the X-ray scattering study vary with temperature and the temperature-dependence is specific for the type of nerve (sciatic or optic). Most of the disorder-related parameters display a minimum or a maximum in the vicinity of physiological temperature (38 degrees C in rat); this observation, strongly supported by the electron microscope study, shows that the degree of organization of myelin is highest near physiological temperature. The structure of the motif, as revealed by the electron density profile, is fairly different in the two types of nerves (in contrast with the assumption made by previous workers); the structure also varies with temperature and the temperature-induced alterations are nerve-type specific. In the two types of nerve the thickness of the lipid bilayer varies with temperature as expected for a lipid-containing system with hydrocarbon chains in the disordered conformation. In sciatic nerve the thickness of the (thinner) cytoplasmic polar layer, which is also the layer most affected by lattice disorder in this type of nerve, decreases dramatically with increasing temperature. In optic nerve, in which lattice disorder predominantly affects the extracellular layer, the thickness of both the cytoplasmic and the extracellular layer is barely affected by temperature.
Asunto(s)
Vaina de Mielina/química , Nervio Óptico/química , Nervio Ciático/química , Algoritmos , Animales , Sistema Nervioso Central/química , Microscopía Electrónica , Vaina de Mielina/ultraestructura , Nervio Óptico/ultraestructura , Ratas , Ratas Sprague-Dawley , Dispersión de Radiación , Nervio Ciático/ultraestructura , Temperatura , Rayos XAsunto(s)
Humanos , Animales , Ácido gamma-Aminobutírico/metabolismo , Glutamato Descarboxilasa/metabolismo , Islotes Pancreáticos/enzimología , Secuencia de Aminoácidos , Autoantígenos , Secuencia de Bases , Sistema Nervioso Central/química , Ciclo del Ácido Cítrico , Glutamato Descarboxilasa/análisis , Glutamato Descarboxilasa/inmunología , Datos de Secuencia MolecularRESUMEN
Este trabajo consiste en la cuantificación de los alcaloides presentes en hojas de brugmansia arborea "floripondio" habiéndose preparado un extracto total alcoholico, y a partir de este un extracto clorofórmico alcaloidico. Su aisló escopolamina de la atropinattiosciamina mediante TLC y se cuantificó espectrofotometicamente a 650nm, encontrándose 0.9 por ciento de alcaloides. Con ambos extractos una vez eliminados los solventes. Se estudió los efectos farmacológicos de dichos alcaloides sobre la memoria. Se utilizó 20 ratones de 3 meses y más de 18 g de peso, que fueron adiestrados en un laberinto durante 7 semanas, lográndose rapidez y que no cometieran errores. A 10 ratones se les administró el extracto total y a 10 el extracto alcaloidico, en cantidad equivalente a 300 mg/k peso de alcaloides, 5 de cada grupo recorrieron el laberinto en fase exitatoria y 5 en fase depresora, observándose que en todos los casos cometieron errores e incrementaron su tiempo de recorrido, lo cual estaba acentuado en los ratones con extracto alcaloidico y en aquellos que se encontraban en fase depresora. Se concluye que los alcaloides presentes afectan la función memoria del SNC, siendo mayor esta alteración con los alcaloides puros, y en la fase depresora.
Asunto(s)
Alcaloides , Alcaloides/análisis , Alcaloides/química , Alcaloides/aislamiento & purificación , Alcaloides/farmacocinética , Alcaloides/farmacología , Sistema Nervioso Central/química , Sistema Nervioso Central/efectos de los fármacos , Memoria/efectos de los fármacos , Espectrofotometría , Espectrofotometría/estadística & datos numéricosRESUMEN
It is generally accepted that the carboxylic amino acids L-Glu and L-Asp play a role as excitatory neurotransmitters at the CNS. In the search of a structure-activity relationship we have made a theoretical conformational analysis with a mechanics molecular model on active compounds on QUIS and NMDA-receptors. We consider the COO-...COO- distance in these compounds as the more important one in order to discuss the different mode of action of this compound at the excitatory amino acid receptors. On QUIS-receptors: We had found that Glu, Asp and QUIS are very flexible molecules that can easily pass from one conformation to another and to get the distance of 3A degrees between the two COO- groups. All these compounds show an important population in conformations with this distance. The antagonist GDEE had 90% of its whole population in folded conformations with a distance of about 3 A degrees between COO-...COO- groups. On NMDA-receptors: IBO is a rigid analogue and the distance COO-...COO- is about 4A degrees at the different conformations found. Asp, Glu, beta-Amglu and NMDA have a considerable flexibility and they can easily adopt the distance required. They leave a considerable population in conformations that present a COO-...COO- distance about 4A degrees. We propose that folded conformations are important for activity on QUIS-receptors, whereas extended conformations are the important on NMDA-receptors.