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  • 1
    Electronic Resource
    Electronic Resource
    Aging: Decline of dopamine-stimulated adenylate cyclase activity inMytilus edulis (Bivalvia) (1982)
    Springer
    Cellular and molecular neurobiology 2 (1982), S. 249-253 
    Details
    ISSN: 1573-6830
    Keywords: aging ; dopamine-stimulated cyclase ; dopamine ; chlorpromazine ; guanyl 5′-yl-imidodiphosphate [Gpp(NH)p] ; invertebrate organism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. Aging is a multivariate process which results from a progressive accumulation alterations including, for example, biochemical and physiological changes, in an organism with time. These alterations occur in short- and long-lived organisms, in invertebrates and vertebrates. 2. The present study demonstrates that the maximum responsiveness and sensitivity of dopamine-stimulated adenylate cyclase diminish with age as determinedin vitro in pedal ganglion homogenates. The dopamine-blocking efficacy of chlorpromazine also decreased with age in 4-year-old organisms compared to 1- and 2-year-old organisms. However, adenylate cyclase activity does not diminish with age in response to the GTP stable analogue, Gpp(NH)p. 3. The results suggest that one aspect of aging inMytilus edulis specifically affects dopamine interaction with this receptor-mediated system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00711152
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  • 2
    Electronic Resource
    Electronic Resource
    Comparative aspects of opioid-dopamine interaction (1982)
    Springer
    Cellular and molecular neurobiology 2 (1982), S. 167-178 
    Details
    ISSN: 1573-6830
    Keywords: dopamine ; opioids ; invertebrate opioid responsiveness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. Opiate receptors are found in invertebrate as well as mammalian systems, often in proximity to dopamergic systems. This review summarizes the interrelationships between these two transmitter systems in invertebrates. 2. The comparative data discussed here are of considerable significance. They recall that the opioid-dopamine relationships first demonstrated in the mammalian nervous system also apply to invertebrates and are therefore of more general importance. The results obtained in the molluskMytilus strengthen the concept that the activity of dopaminergic neurons may be modulated by afferent opioid signals and that, even in “more primitive” animals, interneuronal transfer of information is more complex than formerly visualized. Furthermore, the data indicate that endogenous opioids may exert tonic control over dopamine metabolism, thus implying interdependence of the two systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00711145
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  • 3
    Electronic Resource
    Electronic Resource
    An opioid mechanism modulates central and not peripheral dopaminergic control of ciliary activity in the marine musselMytilus edulis (1986)
    Springer
    Cellular and molecular neurobiology 6 (1986), S. 17-30 
    Details
    ISSN: 1573-6830
    Keywords: opioid mechanisms ; ciliary activity ; morphine ; dopamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. Opioid receptors and enkephalinergic neurons in the central nervous system ofMytilus edulis have been reported. Also known is that the lateral epithelium of the gill is innervated by serotonergic, cilioexcitatory neurons and dopaminergic, cilioinhibitory neurons. The aim of the present report is to look for an effect of opioid agonists on the nervous control of the lateral cilia. 2. Dopamine applied to the cerebral ganglion inhibited the activity of lateral cilia in the gill. This effect was blocked by the application of several opioids to the visceral ganglion. The block was reversed by the application of naloxone to the visceral ganglion. 3. Dopamine applied to the visceral ganglion also inhibited lateral ciliary activity as shown earlier. Opioids applied to the visceral ganglion partially blocked this effect but this was overcome by higher concentrations of dopamine. 4. Preparations with low endogenous rates of ciliary beating were stimulated by the application of opioids to the visceral ganglion. Naloxone blocked this effect. 5. Preparations with high endogenous rates of ciliary beating were inhibited by the application of naloxone to the visceral ganglion. 7. Electrical stimulation of the cerebrovisceral connective produced excitatory and inhibitory effects depending on the rate of stimulation. Morphine applied to the visceral ganglion diminished the cilioinhibitory effects and enhanced the cilioexcitatory effects of electrical stimulation. 8. Morphine applied to the gill had no effect on the cilioinhibitory action of dopamine applied to the visceral ganglion. There was no observable effect of opioids applied to the gill and no alteration in the cilioinhibitory effect of dopamine or the cilioexcitatory effect of serotonin applied directly to the gill in the presence of opioids. 9. Specific opioid binding sites were found in the visceral ganglion but were not found in gill, palp, mantle, or visceral mass tissue. 10. A dopamine-stimulated adenylate cyclase activity was again found in the visceral ganglion and the gill. Etorphine reduced the dopamine stimulation of cyclase in the ganglion but not in the gill. 11. It is postulated that a cilioinhibitory, dopaminergic mechanism includes nerves running from the cerebral ganglion to the gill with synaptic transmission in the visceral ganglion that can be modulated by opioids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00742972
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  • 4
    Electronic Resource
    Electronic Resource
    Aging alterations in the modulation of central dopaminergic cilioinhibition by etorphine in the marine mussel,Mytilus edulis: Decrease in the inhibition of presynaptic dopamine release (1987)
    Springer
    Cellular and molecular neurobiology 7 (1987), S. 209-219 
    Details
    ISSN: 1573-6830
    Keywords: aging ; dopamine ; etorphine ; presynaptic ; Mytilus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. This report further demonstrates that etorphine influences presynaptic dopamine release, which in turn centrally modulates peripheral cilioinhibition. 2. In older animals cilioinhibition has become enhanced due to a lack of responsiveness to endogenous opioids which results in greater dopamine release, causing a higher level of cilioinhibition as demonstrated by challenging the visceral ganglia with etorphine or destroying the dopaminergic component with 6-hydroxydopamine. 3. Only the central cilioinhibitory, not the peripheral inhibitory response, mechanism appears to be altered in older animals. Thus, the alteration appears in the central integrative mechanisms involved with regulating ciliary activity. 4. The KCl-stimulated release of dopamine is unaltered in both young and old organisms, whereas the opiate inhibition of the KCl-stimulated release of dopamine is reduced in older organisms. Thus, the aging-associated alteration is associated with a specific process. 5. The reduction of opioid influence and the resulting enhanced cilioinhibitory activity may make the organisms more susceptible to environmental stress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00711555
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  • 5
    Electronic Resource
    Electronic Resource
    Selective initiation of nonconjugated dienes containing electron donor-electron aceptor systems. I. Synthesis of vinyl ether-β-nitrostyrene monomers (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 1343-1357 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The objectives of this work were to synthesize, characterize, and conduct a polymerization study on a set of ideal crosslinking monomers. The monomers studied are the three isomers of (2-vinyl-oxyethoxy)-β-nitrostyrene. Such monomers contain both the electron-donating vinyl ether moiety and the electron-accepting β-nitrostyrene moiety. A study of the spectral properties of these monomers was carried out in an effort to determine whether there was a contribution to the structure through an intramolecular interaction of the nature of a charge-transfer complex. Such studies have led to little or no support for such an interaction. As model compounds for comparison of spectral properties, the monomer series, o-, m-, and p-(2-ethoxyethoxy)-β-nitrostyrenes were synthesized and characterized as above. A comparison of the spectral and physical properties of these two series of compounds show that there are significant differences suggestive of the interactions proposed. However, since these discrepancies are small in most cases, it is not possible at present to correlate them specifically with the postulated intramolecular interactions.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160615
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  • 6
    Electronic Resource
    Electronic Resource
    Selective initiation of nonconjugated dienes containing electron donor-electron acceptor systems. II. Polymerization studies of vinyl ether-β-nitrostyrenes (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 1359-1365 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The monomer series, o-, m-, and p-(2-vinyloxyethoxy)-β-nitrostyrenes, was studied. All three monomers were selectively polymerized through the electron-donating vinyloxy group via cationic initiation. The linear polymers from the meta and para isomers containing the electron-accepting nitrovinyl group were readily crosslinked via anionic initiation. The polymer derived from the ortho isomer was not crosslinked by this mechanism, an observation in accord with results previously reported from these laboratories in which it was shown that all o-substituted-β-nitrostyrenes having ortho substituents larger than fluorine exhibited a sterically inhibited propagation step. The meta and para isomers of this series were selectively polymerized through the electron-accepting nitrovinyl group via anionic initiation. Because of the fact that the resulting polymers were soluble only in highly polar solvents, subsequent crosslinking of these polymers via cationic initiation could not be accomplished. However, these polymers showed strong tendencies to undergo crosslinking upon long exposure to air. Because of the sterically induced ortho effect referred to above, no significant polymerization occurred in the case of the ortho isomer of this series via anionic initiation. However, it was shown in this case that initiation via the anion was rapid, and that the slow step was propagation.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160616
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  • 7
    Electronic Resource
    Electronic Resource
    Selective initiation of nonconjugated dienes containing electron donor-electron acceptor systems. III. Synthesis of vinyl ether-styrene monomers (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 1367-1373 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In a continuation of our studies on nonconjugated dienes containing electron donor-electron acceptor systems which may function as model crosslinking monomers, we here report the synthesis of the series, 2-, 3-, and 4-(2-vinyloxyethoxy)styrenes. The dipole moments μ, infrared and ultraviolet absorption properties, refractive indices nD30, molar refractions (MRD), and optical exaltations of the compounds were determined. In order to establish whether any intramolecular electronic interactions, e.g., intramolecular charge-transfer complexes, contribute to the structure and properties of these compounds, 2- and 4-(2-ethoxyethoxy)styrenes were also prepared, and their properties compared with those of the vinyloxy series. While there are differences in certain of the properties of these two groups of monomers, these differences are not sufficiently large to permit definite correlations with the proposed interactions.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160617
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  • 8
    Electronic Resource
    Electronic Resource
    Selective initiation of nonconjugated dienes containing electron donor-electron acceptor systems. IV. Polymerization of vinyl ether-styrene monomers (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 1375-1389 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Three isomeric nonconjugated dienes, o-, m- and p-(2-vinyloxyethoxy)styrenes, were selectively polymerized by anionic or radical initiators through the styryl double bond while leaving the vinyl ether moiety intact. The anionic-initiated polymeric products are of high molecular weight and narrow molecular weight distribution as characterized by membrane osmometry and gel-permeation chromatography, respectively. These polymers were subsequently crosslinked by cationic initiators via the vinyl ether moiety on the polymer side chains. Acid-catalyzed hydrolysis of the poly(2-vinyloxyethoxy)styrenes yielded their respective hydroxy-containing polymers, polyvinylphenoxyethanols. The latter were physically and spectroscopically identical to authentic samples prepared by radical polymerization of the corresponding vinylphenoxyethanols, which, in turn, were synthesized by hydrolysis of the (2-vinyloxyethoxy)styrenes. The polyvinylphenoxyethanols were shown to undergo many chemical transformations, such as esterification with 3,5-dinitrobenzoyl chloride, cyanoethylation, and urethane formation.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160618
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  • 9
    Electronic Resource
    Electronic Resource
    Synthesis and properties of alternating copolymers of potential antitumor activity containing 5-fluorouracil (1979)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 351-363 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: “Pyran” copolymer, the 2:1 regularly alternating cyclocopolymer (DVE - MA) of maleic anhydride (MA) and divinyl ether (DVE), first discovered in 1951, has been investigated extensively, both from the standpoint of its chemical structure and its biological activity. Although certain aspects of its structure remain to be determined, it has been shown to possess a wide spectrum of biological activity. It possesses antitumor activity and has been investigated clinically. During the clinical investigation, it was found to be an interferon inducer. Interferon is a protein which appears to be the body's first line of defense against viral infection. DVE - MA also possesses antiviral, antibacterial, antifungal, antiarthritic, and anticoagulant properties, activates macrophages, inhibits reverse transcriptase, and is capable of elimination of Pu. During the course of investigations in these laboratories, many structural modifications of DVE - MA have been made. Many of these modifications also possess considerable antitumor activity and interferon-induction capability. Perhaps the most interesting structural modification has been the incorporation of 5-fluorouracil (5-FU) into the polymer (NSC 255083). This polymer has shown (T/C)% [= ratio of test (T) to control (C) survival times] = 189 for dose by intraperitoneal injection of 200 mg/kg animal weight in CD2F1 mice (6/6 survivors after fifth day) against P388 lymphocytic leukemia. This article describes the synthesis of both the monomer and copolymer, and a study of the hydrolytic rate of release of 5-FU from the polymer.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1979.170170205
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  • 10
    Electronic Resource
    Electronic Resource
    Structure study of the furan-maleic anhydride copolymer (1981)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 19 (1981), S. 1175-1196 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A structural study of furan-maleic anhydride copolymer (F-MAH) was undertaken to confirm its alternating nature and to determine its microstructure. The spectral properties of a model compound representing the alternating repeat unit, 2-(2-tetrahydrofuranyl)succinic anhydride, were compared with those of F-MAH. Their infrared (IR), 1H, and 13C nuclear magnetic resonance (NMR) spectra (after compensating for the absence of the olefinic double bond) were in good agreement with those of the copolymer. Furthermore, the observed splitting in the 1H- and 13C-NMR spectra of F-MAH were assigned to cis-trans linkages on both the F and MAH units, with cis linkage being favored on both units, especially the former. The structure of 2,5-dimethylfuran (DMeF)-MAH copolymer is similar to that of F-MAH copolymer, except that the preference of cis linkages is less pronounced. The structure of 2-methylfuran (MF)-MAH copolymer is a complex structure with numerous 2,3-furandiyl units. A mechanistic study was undertaken to elucidate the roles of F-MAH Diels-Alder adduct, and the charge-transfer (CT) complex in the radical initiated copolymerization. The adduct reverted substantially to monomers under the reaction conditions; but, the amount of adduct remaining at equilibrium was quite appreciable; therefore, its participation could be ruled out on this basis alone. However, on polymerizing the adduct in the presence of F-d4, the latter was incorporated into the copolymer to an extent indicative of free monomer exchange. Therefore, the adduct cannot be directly involved in the polymerization.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1981.170190514
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