Simone Florim da Silva

Essential oil composition of Melissa officinalis L. in vitro produced under the influence of growth regulators

It was investigated the effects of indole-3-acetic acid (11.42 µmol L-1), benzylaminopurine (8.87 µmol L-1) on essential oil composition and on the growth of Melissa officinalis in vitro plants. In vitro plantlets developed on MS media, showed 1.4 times in the proportion of nerol and 4.1 of geraniol, when compared with ex vitro plants. Treatments with 11.42 µmol L-1 indole-3-acetic acid plus 8.87 µmol L-1 benzylaminopurine led to 1.7 and 2.2 fold in proportion of nerol and geraniol, respectively in 60-day-old whole plants. These increases might be associated with the action of growth regulators wich stimulate plant growth (shoot organogenesis and elongation) and delaying the alcohol oxidation to aldehydes.

Glial fibrillary acidic protein (GFAP)-like immunoreactivity in the visual system of the crab Ucides cordatus (Crustacea, Decapoda)

Abstract Glial fibrillary acidic protein (GFAP) is the main intermediate filament protein used as a marker for the identification of astrocytes in the central nervous system of vertebrates. Analogous filaments have been observed in the glial cells of many mollusks and annelids but not in crustaceans. The present study was carried out to identify by light microscopy immunohistochemistry, immunoelectronmicroscopy and immunoblotting, GFAP‐like positive structures in the visual system of the crab Ucides cordatus as additional information to help detect and classify glial cells in crustaceans. Conventional electron microscopy, light microscopy of semithin sections and fluorescence light microscopy were also employed to characterize cells and tissues morphology. Our results indicated the presence of GFAP‐like positive cell processes and cell bodies in the retina and adjoining optic lobe. The labeling pattern on the reactive profiles was continuous and very well defined, differing considerably from what has been previously reported in the central nervous system of some mollusks, where a diffuse spotted fluorescence pattern of labeling was observed. We suggest that this glial filament protein may be conserved in the evolution of the invertebrate nervous systems and that it may be used as a label for some types of glial cells in the crab.

Glial Cells of the Central Nervous System in the Crab Ucides cordatus

Glial cells and their processes were characterized in the fasciculated zone and in the protocerebral tract of the crab Ucides cordatus by light and electron microscopy. Thiery and PAS procedures indicate the presence of carbohydrates, particularly glycogen in cells. Immunohistochemistry was used to observe tubulin distribution in the glial cells. Our results demonstrate at least two types of glial cells in the fasciculated zone and in the protocerebral tract, separable by their location and electron density. Judging by their position, electron-lucent cells may correspond to periaxonal cells and electron-dense ones may correspond to perineurial cells. The electron-dense processes have previously been interpreted as extracellular matrix, but since they feature an enveloping membrane and contain glycogen and mitochondria (intact and with varying degrees of disruption) we consider them to be part of one type of glial cells. Additional key words: Crustacea, Malacostraca, Brachyura, glia Invertebrate glial cells have traditionally been classified according to certain relatively general morphological or functional criteria and also by their anatomical position (Haimori & Horridge 1966; Radojcic & Pentreath 1979). Because invertebrates do not have true compact myelin, no glial class equivalent to vertebrate oligodendrocytes can be identified. In addition, immunocytochemical markers for vertebrate astrocytes in most cases fail to label invertebrate glia. (One of the exceptions is glutamine synthetase, a specific marker for astrocytes in vertebrates, which has also successfully labeled non-neuronal cells in lobster olfactory regions: Linser et al. 1997.) The glial cell types of arthropods share many morphological characteristics. First, in many species, the chromatin of glial cell nuclei is clumped in the periphery. This feature is rarely seen in neuronal nuclei. Second, mitochondria, endoplasmic reticulum, and Golgi structures are generally common. Third, between neighboring glial cells and also between glial cells and neurons, diverse membrane specializations are found (see Pentreath 1987). In the nervous system of some species of higher crustaceans, i.e., Decapoda, there is good anatomical and physiological evidence for an insulating sheath with nodes and rapid saltatory conduction (Heuser & Doggenweiler 1966). Where present, the sheath coma Author for correspondence. E-mail: sallodi@chagas.biof.ufrj.br prises numerous laminae, each containing cytoplasm and forming a seam. The nodes are loosely wrapped by a characteristic type of glial cell called the nodal cell. The axons can be wrapped either simply by a single glial process or in groups, by complex, tightly packed multiple layers, resembling vertebrate myelin (Bullock et al. 1977). Important differences from vertebrate myelin are: (a) the crustacean laminae do not connect to form a spiral; (b) the nuclei of the sheath cells lie on the inside of the sheath; (c) desmosomes join adjacent laminae; (d) sometimes an adjacent extracellular matrix may occur between neighboring glial cell processes (Heuser & Doggenweiler 1966). The participation of neuroglia in the blood-brain barrier is an important function of glial cells in both vertebrates and invertebrates (Abbott et al. 1986; Abbott 1995). Unlike the situation in higher vertebrates, in which the blood-brain barrier is formed by tight junctions of endothelial cells lining capillaries of the central nervous system (see Peters et al. 1991), the barrier in crustaceans is formed by glial perineurium surrounding the ganglia. The sealing function of the barrier is thought to be due to the junctions between the perineurial cells and the extracellular matrix, which may be expanded and contain collagen-like fibrils (Abbott 1972; see Pentreath 1987). The most widely accepted function of glial cells is that they interact metabolically with neurons, providing nutrients, exchanging metabolites, and removing catabolites. Such a role is supported by glial stores of glycogen This content downloaded from 157.55.39.231 on Wed, 05 Oct 2016 04:16:00 UTC All use subject to http://about.jstor.org/terms Allodi, Silva, & Taffarel and large numbers of vesicular and granular inclusions in the cytoplasm (Pentreath 1987; Tsacopoulos & Magistretti 1996). Our goal was to characterize the organization of glial cells and their processes by light microscopy (LM) and transmission electron microscopy (TEM) and to correlate those findings with the distribution of extracellular matrix in the fasciculated zone (FZ) and in the protocerebral tract (PT) of the crab Ucides cordatus. The FZ comprises retinular cell axons that run from the retina to the lamina ganglionaris (Bell & Lightner 1988) and the PT is the tract that links the terminal medulla and the hemiellipsoid body to the anterior medial protocerebral neuropil and other areas of the brain (Sandeman et al. 1992). These neuropils were chosen because they are primarily composed of axons and glial cells.

Crustacean visual system: an investigation on glial cells and their relation to extracellular matrix.

Summry— Glial cells in higher invertebrate groups are usually recognized on the basis of their location and general morphological or functional criteria. In this study of the crustacean visual system, we have approached the analysis of the relations between glial cells and the extracellular matrix by classical histochemical methods for carbohydrates at the light and electron microscopic levels, carbonic anhydrase histochemistry and by the biochemical characterization of sulphated polysaccharides. Periodic acid—Schiff‐positive glial cells and processes were observed in the retina, basement membrane below the retina and in the optic ganglia. Carbonic anhydrase was not detected in the retina but it was demonstrated in all optic ganglia. The biochemical analysis of the extracellular matrix confirmed the alcian blue reaction and showed that sulphated polysaccharides are not abundant in the optic neuropils. This article describes into more details the crustacean visual system glial cells classification, and the relation between them and the extracellular matrix. In addition, they show that glial cells are the main components of the retinal basement membrane.

Binding of an antibody against a noncompact myelin protein to presumptive glial cells in the visual system of the crab Ucides cordatus

Glial cells, in both vertebrate and invertebrate nervous systems, provide an essential environment for developmental, supportive, and physiological functions. However, information on glial cells themselves and on glial cell markers, with the exception of those of Drosophila and other insects, is not abundant in invertebrate organisms. A common ultrastructural feature of invertebrate nervous systems is that layers of glial cell cytoplasm‐rich processes ensheath axons and neuronal and glial somata. In the present study, we have examined the binding of a monoclonal antibody to 2′,3′‐cyclic nucleotide 3′‐phosphodiesterase (CNPase) in the compound eye and optic lobe of the crab Ucides cordatus using both light and electron microscopy. CNPase is a noncompact myelin protein that is a phenotypic marker of oligodendroglial and Schwann cells, is apparently involved in the ensheathment step prior to myelin compaction, and is also expressed by the potentially myelinating olfactory ensheathing glia. CNPase has raised much interest, first by virtue of its unusual enzymatic activity and more recently by its membrane‐skeletal features and possible involvement in migration or expansion of membranes. We have found CNPase‐like immunoreactivity in most cells of the compound eye basement membrane and both in optic cartridges of the synaptic layer and cells of the outer sublayer of the lamina ganglionaris. The results suggest that in the crab visual system some, but not all, glial cells, including some adaxonal glia, may express the noncompact myelin protein CNPase or a related protein. GLIA 9999:000–000, 2003.

Capital Control Over Higher Education

The financialization of wealth implies pressure on social policies – a context under which education and scientific development have become very important niches for the financial market. Their undertaking by private organizations, however, is not new: it was started during the corporate-military dictatorship, authorized and stimulated by the 1968 University Reform (Law 5.540 – Brasil, 1968) which addressed claims for expanding access to higher education.

Education and Financial Capital

In order to understand the commodification of Brazilian education, in our perspective it is necessary to depart from the observation of contemporary capitalism and from the identification of the financial sector as the most powerful fraction of capital. Therefore, we choose to start this book with a chapter about financialization and its relation with education, specifically approaching the participation of the open-capital private sector in the production of school material and in the offering of other services in public education.