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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 88 (1966), S. 4178-4184 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Anatomia, histologia, embryologia 22 (1993), S. 0 
    ISSN: 1439-0264
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The ultrastructural modifications that occur on the ependymal surface of the lateral ventricles of prenatal rabbit brains at 25, 27, 29 days of pregnancy, of term fetuses (30–31 days) and of 5, 10, 15 day old newborn rabbits, were studied by a SEM. On the ependymal surface the cilia, usually associated in tufts and the microvilli, variable in size and number, that surround them, show a rate of development correlated to the age. The results show the early differentiation of the surface features commensurated with early cerebrospinal fluid (CSF) functioning.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Anatomia, histologia, embryologia 27 (1998), S. 0 
    ISSN: 1439-0264
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Morphological and immunohistochemical studies carried out particularly around the level of the basal ganglia (BG) in birds, are reported and commented on.Our results showed, on paraffin embedded avian BG, both the histological features and the immunohistochemical findings on immunofluorescence distribution of some neuropeptides (especially Metenkephalin) in the striatal complex. By comparing our results of Metenkephalin immunoreactivity (Menkir) with the referred analogous ones of Substance P (SP) quoted in literature, we confirmed the strikingly similar labelling at the levels of the Lobus paraolfactorius (LPO) and Paleostriatum augmentatum (PA), in contrast with the very low immunoreactivity at the Paleostriatum primitivum (PP) levels. We were able also to demonstrate the strong MEnk-ir of the neurons of the Nucleus accumbens, Nucleus septalis and paraventricularis. All these findings are also in accord to the interpretation by many AA (Wynne and Gunturkun. 1995; Reinez et al., 1983). about the anatomical correspondence between the LPO-PA complex of birds and the caudate-putamen in mammals. Some MEnk +‘wooly like fibres’ described in our specimens in the PA (on the contrary reported in the Gpe segment of mammals) apparently escape these correspondence.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Berlin, Germany : Blackwell Verlag GmbH
    Anatomia, histologia, embryologia 34 (2005), S. 0 
    ISSN: 1439-0264
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The oral cavity in vertebrates plays a very important role in food intake mechanics and also contains chemical sensors for food and environmental water. Comparative studies revealed morphological and functional inter-specific differences that can be correlated to evolutionary events and might represent the adaptation to environmental conditions present in different habitats (Iwasaki, 2002). Particularly these events are strictly dependent on the food intake mechanisms determining the success of the adaptation of vertebrates to their environment and therefore their survival (Roth and Wake, 1989). Since data about the morphology of the zebrafish oral cavity are scarce the aim of the present research was to study it by light, scanning and transmission electron microscopy and immunohistochemistry for some growth factor receptors, i.e. trkA and trkB. The zebrafish was chosen because as a vertebrate it has valuable features as a model for study of vertebrate development (Withfield, 2002). Adult zebrafishes were anesthesized with MS222 and the samples were taken and routinely processed for light and electron microscopy and for indirect peroxidase immunohistochemistry. The topographical and ultrastructural study demonstrated the presence of three different zones. The outer zone is characterized orally by the presence of a papilla and by an epithelium with numerous taste buds that are chemosensory endorgans consisting of modified epithelial cells. Their function is to sample potential food and selecting it according to its edibility (Hansen et al., 2002). Both in upper and lower intermediate zones, the presence of internal valves with a semi-lunar shape was evident, probably able to regulate the mouth closure. The most internal lower zone corresponds to the tongue that in zebrafish is only a thickening of the pavement mucosa with a stratified epithelium. Immunohistochemistry demonstrated both in upper and lower zones the presence of numerous taste buds that were immunoreactive to TrkA and TrkB-like neurotrophin receptors, confirming the role of these receptors in taste buds sensory cells (Germanà et al., 2004). The present results give a contribution to the morphological knowledge of the zebrafish oral cavity, an animal model commonly used for developmental studies of vertebrates.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Berlin, Germany : Blackwell Verlag GmbH
    Anatomia, histologia, embryologia 34 (2005), S. 0 
    ISSN: 1439-0264
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The lateral line system (LLS) is a sensory organ present in fishes and in the larval stage of aquatic amphibians, which provides the animal with information about its surrounding environment. Mechanoreceptive sensory cells in the LLS of fishes are grouped into neuromasts that are considered the morphological unit of this system. Structurally the neuromast consists of a central cluster of hair cells with a ring of support cells with some lateral mantle cells. The LLS is localized in both the body surface (superficial neuromast or pit organs) and in a system of canals distributed along the head, trunk and tail (deep neuromast) (Cernuda-Cernuda et al., 1996). The study of hair cells in the neuromast of fishes is becoming of a great interest, since they are similar in structure and function to the sensory cells of the inner ear and show some identical immunohistochemical properties (Foster et al., 1993). Recently, we have demonstrated the occurrence and the presence of S100 protein in the neuromast hair cells of some teleostean species (Abbate et al., 2002; Germanà et al., 2004). The zebrafish has become an ideal model for the study of developmental genetics, and the neuromast has been used as a model for the study of vertebrate auditory system (Withfield, 2002), so the need for cell selective markers has increased dramatically. Therefore, in this study we have investigated by tissue and whole-mount immunohistochemistry the presence of S100 protein in both deep and superficial neuromasts in the zebrafish larval, juvenile and adult stages. The results of this work demonstrated that the localization of S100 protein was restricted only to the hair cells of the neuromast at all the examined ages. The mantle cells and supporting cells within the neuromast were unreactive. Nevertheless, heterogeneity has been detected in the S100 protein expression by hair cells, independent of their localization within the neuromast. Our data suggest that the S100 protein is a specific marker for sensory cells in the neuromast of zebrafish at post-embryonic different stages of development, and it could be important for the analysis of development, regeneration and turnover of hair cells.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-2072
    Keywords: Key words Prefrontal cortex ; Dopamine ; Anxiety ; Drug discrimination ; Pentylenetetrazol ; Chlordiazepoxide ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Rationale: The prefrontal cortical (PFC) dopamine (DA) system has been implicated in anxiety-related behavioral changes, but direct, unequivocal support for this idea is sparse. Objectives: The present aim was to study the functional significance of prefrontal DA using the pentylenetetrazol (PTZ) discrimination model of anxiety. A comparison was made with its role in the cue of the anxiolytic drug chlordiazepoxide (CDP). Methods: Two groups of rats were trained to discriminate either PTZ (20 mg/kg, s.c.) or CDP (10 mg/kg, i.p.) from saline using an operant drug discrimination procedure. After prolonged training, half of each group was used to assess biochemical changes induced by both drugs in different sub areas of the PFC. For the remaining rats, discrimination training continued and generalization tests with PTZ and CDP were performed. Rats were then provided with bilateral guide cannulae aimed at the ventromedial (vm) PFC, and the effects of local infusions of DAergic drugs on discriminative performance were evaluated. Results: CDP did not affect PFC DA activity, but PTZ increased the DOPAC/DA ratio in the vmPFC selectively. Generalization tests showed that the cues of PTZ and CDP were dose dependent. In PTZ-trained rats, infusions of the DA receptor antagonist cis-flupenthixol into the vmPFC blocked the PTZ cue dose dependently, whereas the agonist apomorphine partially generalized to this cue. In CDP-trained rats, neither drug antagonized or generalized to the CDP cue, showing that PFC DA is not critically involved in the CDP cue and that local pharmacological manipulations of PFC DA do not affect discriminative abilities per se. Conclusions: The DAergic innervation of the PFC is directly involved in the behavioral effects of PTZ, suggesting a role for it in anxiety.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1433-0350
    Keywords: Escherichia coli ; Infection ; Choroid plexus ; Hydrocephalus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Gram-negative bacterial infections of the central nervous system are generally associated with high morbidity and mortality rates. In patients with ventriculitis induced by gram-negative liquoral sepsis, a reduction in cerebrospinal fluid formation has been reported, suggesting that gram-negative ventriculitis is able per se to alter the normal functioning of the choroid plexus. The aim of the present study was to analyse, for the first time in the rat, the effects of tcute ventriculitis on the ultrastructure of the choroid plexus. A simple and inexpensive experimental model of acute ventriculitis was developed: we injected into the cisterna magna of rats 103 CFU of liveEscherichia coli, inducing septic ventriculitis without major neurological deficits. Histological examinations of rodent choroid plexus 24 h after the injection revealed patches of altered epithelium, with swollen and vacuolated ependymal cells associated with leukocyte infiltration. Electron microscopy demonstrated a reduced number of microvilli and flattening of the epithelial surface. These results (a) indicate that gramnegative septic ventriculitis is able to induce visible ultrastructural alterations of the choroid plexus which (b) are consitent with a picture of marked reduction of the functioning epithelial choroid plexus surface, and (c) highlight the potential usefulness of our rodent acute ventriculitis model for developing treatment modalities.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-0878
    Keywords: Neurotrophins Trk neurotrophin receptor proteins Non-nervous tissues Immunohistochemistry Dicentrarchus labrax (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In recent years, data have accumulated suggesting that the role of neurotrophins and Trk receptors may not be limited to the nervous system, and the presence of these substances has been detected in a variety of vertebrate and invertebrate non-nervous tissues. This study was designed to map the expression of immunoreactivity (IR) for Trk-like proteins in alevins of the teleost Dicentrarchus labrax, with particular emphasis on non-nervous structures. We used antibodies against specific epitopes of the intracellular domain of these proteins, a region that is highly conserved in phylogeny. Trk-like IR was seen in segregate cell populations of the nervous system, and non-nervous tissues. In the central nervous system TrkA-like and TrkC-like IR was abundant, whereas TrkB-like IR was restricted to a low number of brain areas. Expression of Trk-like protein IR was observed in the peripheral nervous system and sensory organs, with the exception of the lateral line organ. Outside the nervous system, TrkA-like IR was mainly found in different epithelia, TrkB-like IR in the endocrine and digestive system, and TrkC-like IR in the cardiovascular and immune systems. The gills showed IR for all three Trk-like proteins, whereas they were absent from the gonads. Furthermore, scattered cells positive for Trk-like proteins were found in most of the investigated tissues. The distribution of Trk-like IR in this teleost is compared with that of mammals and birds, which it often paralleled, and the possible role of neurotrophins and Trk-like receptor proteins in different non-neuronal tissues is discussed.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 16 (1972), S. 1213-1234 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The amine-catalyzed, low-temperature (〈 200°C) thermal degradation of aromatic urethanes, specifically carbanilates, was studied to determine the primary reactions responsible for the loss of starting material and the resultant products. The primary degradation reactions are (1) the reversible dissociation of the urethane to isocyanate and alcohol and (2) the nonreversible nucleophilic attack by a basic species on the carbon attached to the carbamate oxygen to yield amine, carbon dioxide, and an alkylated base. Secondary products fall into two categories, neutral and basic species. The neutral components consist of carbanilide, dialkyl carbonate, isocyanurate, and N-alkylated carbamates. The basic components, derived from starting materials, are pseudoureas and guanidines. Their formation depends solely on the presence of carbanilide in the reaction mixture. When the amine catalyst is 1,4-diaza[2.2.2]bicyclooctane, novel piperazine compounds are formed. In general, quarternized triethylenediamine species undergo nucleophilic displacement reactions to form N-alkyl-N′-ethylpiperazine derivatives.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The catalysis of the reaction of n-butyl alcohol with isocyanates, using organometallic derivatives of lead, tin, and mercury, has been investigated. The rate of the reaction was measured by following the disappearance of the isocyanate absorption in the infrared. Phenyl, n-butyl, and cyclohexyl isocyanate were chosen to represent typical aromatic primary and secondary aliphatic isocyanates. Within the same series of catalysts, RnMOAc, the catalytic effect decreases in the order RHg 〉 R3Sn 〉 R3Pb; and in all cases R = aryl 〉 R = alkyl. The electronic effects of substituents on the aryl moiety are not pronounced. Changes in X of RnMX greatly affect the catalytic activity. The mechanism of organometallic catalysis of the alcohol-isocyanate reaction occurs via a template-type mechanism whereby the catalyst acts to complex both reactants in a catalyst phase allowing the reaction to occur with greater facility.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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