Showing papers by "Rio de Janeiro State University published in 1986"
TL;DR: This work produced a monoclonal antibody (JONES) which shows a pronounced dorsal to ventral gradient of binding in the rat retina throughout the period when retinal ganglion cell axons are forming topographically organized projections within the central nervous system (CNS).
Abstract: Brain topography may have its earliest expression as spatial gradients of molecules controlling the deposition of neurones and neuronal processes. In the vertebrate visual system there is evidence that the stereotyped alignment of central retinal projections relies on an initial spatially organized distribution of molecules in both the retina and its central target nuclei. We used an immunological approach to look for molecules that are so organized and produced a monoclonal antibody (JONES) which shows a pronounced dorsal to ventral gradient of binding in the rat retina throughout the period when retinal ganglion cell axons are forming topographically organized projections within the central nervous system (CNS). Binding is present throughout the radial thickness of the retinal epithelium in regions where postmitotic neurones are generated but is not associated with any consistent histological characteristic of the tissue. The antibody was shown to bind on the cell surface of freshly dissociated retinal cells, and dorsal retinal quadrants were found in vitro to have nearly twice as much antigen as ventral retinal quadrants. Initial biochemical characterization of the target epitope reveals that it is a lipid present in chloroform/methanol extracts from perinatal retina and is sensitive to neuraminidase digestion.
183 citations
TL;DR: The electrophysiological results showed that, at all ages examined, early enucleation resulted in an orderly but expanded map in the SC restricted to the sector of the visual field seen by the temporal retina.
22 citations
TL;DR: Two groups of pregnant mice were gamma-irradiated at the 16th gestation day with doses of 2 or 3 Gy, and while the 3-Gy mice showed a severely hypotrophic neocortex without the aberrant longitudinal bundle typical of early disconnected rodents, in the 2-Gy group the cortex was less deranged and the aberant bundle appeared consistently underneath the white matter.
22 citations
TL;DR: Interpopulation studies support the hypothesis of a causal relationship between sodium consumption and arterial hypertension, and although this association has been contradicted by intrapopulation studies, the correlation between sodium and hypertension appears to be genetically determined, as there are both sodium-sensitive and sodium-resistant individuals.
Abstract: Interpopulation studies support the hypothesis of a causal relationship between sodium consumption and arterial hypertension. However, although this association has been contradicted by intrapopulation studies, the correlation between sodium and hypertension appears to be genetically determined, as there are both sodium-sensitive and sodium-resistant individuals. Sodium is essential for the maintenance of extracellular and plasma volume equilibrium. It is controlled metabolically by the interaction of several biological systems such as the renin-angiotensin-aldosterone system, the sympathetic nervous system, and the kallikrein-kinin and prostaglandin systems. Thus, sodium has a definite role in the mechanism involved in the pathophysiology of the predominantly volume-dependent forms of arterial hypertension. Recently, different structural substances with natriuretic effects have been identified. Natriuretic hormone is a non-peptide substance which inhibits the Na,K-ATPase in response to extracellular volume increase. This hormone acts on the renal tubular cells reducing sodium reabsorption, and at an arteriolar level elevating peripheral resistance by increasing smooth muscle tension. Mammalian atria contain various precursors of biologically active peptides, with potent natriuretic and diuretic effects. They are released in response to volume loading and atrial stretch. Although some data suggest an important role for these natriuretic substances in fluid volume and blood pressure control, their place in physiology and in abnormal clinical states should be more definitively clarified in the next few years.
21 citations
TL;DR: Intraplantar injections of PAF or the pre-treatment with the PAF antagonist BN 52021 did not block the edematogenic response induced by carrageenan, and the analogue 2-methyl carbamate-PAF was more effective than PAF as a desensitizing agent.
18 citations
TL;DR: Lungs provided by the sensitized animals secreted histamine and formed thromboxane A2 when challenged with ovalbumin, but failed to do so when the lungs were collected after systemic shock; demonstrating that in vivo desensitization involves direct effects on the lungs.
16 citations
01 Jan 1986
14 citations
TL;DR: Evidence is provided that the eradication of Neisseria carriage is a multifactorial event and bacterial adherence was found to be mediated by nonpiliated adhesins with antigen(s) which probably are shared by the strains tested.
Abstract: Nasal secretions of volunteers colonized by N. lactamica impaired the attachment of N. lactamica and of meningococci of groups A and B to oroepithelial cells. Bacterial adherence was found to be mediated by nonpiliated adhesins with antigen(s) which probably are shared by the strains tested. Although a strong attachment-inhibiting activity arises in their nasal secretions, volunteers remained colonized by N. lactamica. This evidence suggest that the eradication of Neisseria carriage is a multifactorial event.
10 citations
TL;DR: The presente trabalho objetiva a analise da aplicabilidade dos cuidados de enfermagem na administracao de medicamentos num Hospital Universitario X, na cidade do Rio de Janeiro as mentioned in this paper.
Abstract: O presente trabalho objetiva a analise da aplicabilidade dos cuidados de enfermagem na administracao de medicamentos num Hospital Universitario X, na cidade do Rio de Janeiro. Esta analise, elaborada atraves do metodo descritivo e das tecnicas de investigacao social e estudo bibliografico, utilizou a aplicacao de formularios a populacao alvo no periodo de abril/1985, contendo questoes que abordavam as variaveis levantadas pelo tema. Concluiu-se o trabalho com o alcance do objetivo proposto, observando-se que o nivel de conhecimentos acerca de farmacologia, que expressa a qualificacao profissional, foi verificado como Insuficiente, entre a populacao pesquisada.
10 citations
TL;DR: The presente trabajo busca discutir algunas cuestiones relacionadas a la teoria de la resistencia a traves de examen de los datos obtenidos in una investigación de tipo etnografico sobre la interaccion of alumnos and profesores en el cotidiano de una escuela primaria publica em Rio de Janeiro as mentioned in this paper.
Abstract: El presente trabajo busca discutir algunas cuestiones relacionadas a la teoria de la resistencia a traves de examen de los datos obtenidos en una investigacion de tipo etnografico sobre la interaccion de alumnos y profesores en el cotidiano de una escuela primaria publica em Rio de Janeiro.
8 citations
TL;DR: Experimental results suggest that amino acid residues, possibly containing carboxyl and sulfhydryl groups, control the opening and closing of junctional channels and may thus be associated with the channels' active sites.
Abstract: The lateral giant axons of the crayfish nerve cord are composed of segments contributed by each ganglion, which are electrotonically coupled by way of gap junctions. We have investigated the involvement of protein residues in regulating the resistance of crayfish junctional channels by determining effects of group-specific protein reagents. When applied to well-coupled axons, the sulfhydryl group reagents N-ethylmaleimide (NEM) and diamide uncoupled the segments; junctional resistance (Rj) was increased without changing membrane resistance or axoplasmic pH (pHi). The uncoupling produced by NEM could be reversed by alkalinization of the cytoplasm (addition of ammonium chloride to the external medium). Another sulfhydryl reagent (p-chloromercuribenzoic acid) increased Rj to a lesser extent. A disulfide reagent and three amino and three carboxyl group reagents had no effect on the Rj of these axons. The effect of group-specific reagents on partially uncoupled axons was tested by applying the drugs to axons previously exposed to weak acids. N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline recoupled partially uncoupled axons by decreasing Rj and prevented subsequent uncoupling of the junction by low pHi. Another carboxyl group reagent, as well as sulfhydryl and amino group reagents, either had no effect or uncoupled the axons further by increasing Rj. These experimental results suggest that amino acid residues, possibly containing carboxyl and sulfhydryl groups, control the opening and closing of junctional channels and may thus be associated with the channels' active sites.
TL;DR: Exposure of λ phage to triplet acetone, generated via the oxidation of isobutanal by peroxidase, leads to genome lesions that are detected as DNA single-strand breaks only under alkaline conditions, and true breaks do not occur.
Abstract: Exposure of λ phage to triplet acetone, generated via the oxidation of isobutanal by peroxidase, leads to genome lesions. The majority of these lesions are detected as DNA single-strand breaks only under alkaline conditions, and so true breaks do not occur. Also, no sites sensitive to UV-endonuclease from Micrococcus leteus were found in DNA from treated phage. The participation of triplet acetone in the generation of such DNA damage is discussed.
TL;DR: The results suggest that the DNA damage induced in E. coli by H2O2 generated in oxidized ascorbate solutions is different from that induced by direct H2 O2 treatment.
Journal Article•
07 Jul 1986
TL;DR: The quantitative results show that the cells from CT were more closely relationed with IAS cells than others cells (IVS and AVB cells), but this results are not a morphological evidence to establish the specificity of the "internodal posterior tract".
Abstract: The mechanism by which the cardiac impulse is propagated in normal hearts from its origin in the sinus node to the atrio-ventricular node has not been agreed on fully. We studied the "internodal posterior tract" through the crista terminalis by light microscopy and stereological morphometry. The hearts of 12 Papio cynocephalus were perfused , after sacrifice,with phosphate-buffered formol saline. The regions of the crista terminalis (CT), interatrial septum (IAS), atrioventricular bundle (AVB) and interventricular septum (IVS) were cut off and embedded in paraplast and sectioned (10 4m). The multipurpose test system M 42 was superimposed over the photomicrographs (1,890 points test, ESR = 2%) to the stereological computing. The quantitative results show that the cells from CT were more closely relationed with IAS cells than others cells (IVS and AVB cells). This results are not a morphological evidence to establish the specificity of the "internodal posterior tract". The cellular arrangement and anatomical variation in CT myocardium is very important.