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  • Epilepsy  (2)
  • 27.70.+ q  (1)
  • Cocaine self-administration  (1)
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Erscheinungszeitraum
  • 1
    ISSN: 1432-0533
    Schlagwort(e): Key words Neurodegeneration ; Epilepsy ; Kainic acid ; fos ; Gliosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Periodic acid-Schiff (PAS)-positive deposits have been demonstrated in the central nervous system (CNS) of patients suffering from a wide variety of neurodegenerative disorders including Alzheimer's disease, presenile dementia, Parkinson's disease, diabetes mellitus, myoclonic epilepsy, and cerebral palsy. The etiology of these deposits and their relationship to mechanisms of progressive neurodegeneration is unknown. In the present study, we demonstrate that the kainic acid model of limbic status epilepticus provides a useful system for the study of PAS-positive staining. The relationship between PAS-positive deposition, induction of fos-like immunoreactivity (FLI), neuronal necrosis, reactive gliosis, and blood-brain barrier breakdown following the kainic acid induction of status epilepticus was investigated. Epileptiform activity was elicited in rats by intraperitoneal administration of 10 mg/kg kainic acid and brains were examined 3, 5, 12, 24, 72, and 168 h after drug injection. Four distinct types of PAS-positive staining in rat brain were observed: type 1, extracellular matrix (ECM) or blood vessel associated-material; type 2, granular deposits; type 3, glial labelling; and type 4, neuronal labelling. Results demonstrated that the four types of PAS-positive staining were differentially associated with specific markers of neuropathology: (1) type 1 ECM staining and type 3 glia were preferentially localized to edematous tissue; (2) the majority of type 3 glia were identified as reactive astrocytes, while a minority of appeared to be proliferating microglia; (3) type 1 blood vessels labelled hemorrhaging vasculature; (4) early deposition of type 2 granules was predictive of subsequent cell loss; (5) chronic type 2 granular deposits and type 4 neuronal labelling not associated with cell death could be predicted by early changes in FLI; and (6) chronic deposition of all four forms of PAS-positive material was correlated with earlier, transient blood-brain barrier compromise. The results support the growing literature that local carbohydrate metabolism may be one of a constellation of parameters important to the development of progressive neurodegeneration.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1432-0533
    Schlagwort(e): Neurodegeneration ; Epilepsy ; Kainic acid fos ; Gliosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Periodic acid-Schiff (PAS)-positive deposits have been demonstrated in the central nervous system (CNS) of patients suffering from a wide variety of neurodegenerative disorders including Alzheimer's disease, presenile dementia, Parkinson's disease, diabetes mellitus, myoclonic epilepsy, and cerebral palsy. The etiology of these deposits and their relationship to mechanisms of progressive neurodegeneration is unknown. In the present study, we demonstrate that the kainic acid model of limbic status epilepticus provides a useful system for the study of PAS-positive staining. The relationship between PAS-positive deposition, induction of fos-like immunoreactivity (FLI), neuronal necrosis, reactive gliosis, and blood-brain barrier breakdown following the kainic acid induction of status epilepticus was investigated. Epileptiform activity was elicited in rats by intraperitoneal administration of 10 mg/kg kainic acid and brains were examined 3, 5, 12, 24, 72, and 168 h after drug injection. Four distinct types of PAS-positive staining in rat brain were observed: type 1, extracellular matrix (ECM) or blood vessel associated-material; type 2, granular deposits; type 3, glial labelling; and type 4, neuronal labelling. Results demonstrated that the four types of PAS-positive staining were differentially associated with specific markers of neuropathology: (1) type 1 ECM staining and type 3 glia were preferentially localized to edematous tissue; (2) the majority of type 3 glia were identified as reactive astrocytes, while a minority of appeared to be proliferating microglia; (3) type 1 blood vessels labelled hemorrhaging vasculature; (4) early deposition of type 2 granules was predictive of subsequent cell loss; (5) chronic type 2 granular deposits and type 4 neuronal labelling not associated with cell death could be predicted by early changes in FLI; and (6) chronic deposition of all four forms of PAS-positive material was correlated with earlier, transient blood-brain barrier compromise. The results support the growing literature that local carbohydrate metabolism may be one of a constellation of parameters important to the development of progressive neurodegeneration.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 98 (1989), S. 408-411 
    ISSN: 1432-2072
    Schlagwort(e): Gender ; Estrous cycle ; Cocaine self-administration ; Fixed ratio one ; Progressive ratio schedule
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Although it has been demonstrated that many of the behavioral responses to psychomotor stimulants are gender dependent and hormonally sensitive, few studies have examined the possibility that the estrous cycle interacts with drug reinforcement in laboratory animals. The present experiment assessed the effect of the estrous cycle on two aspects of cocaine self-administration behavior: the breaking point on a progressive ratio (PR) schedule and the rate of cocaine intake on a fixed ratio one (FR1) schedule. On the PR schedule, the first lever response produced a drug infusion. Subsequent response requirements escalated with each injection until the behavior extinguished. Breaking points were defined as the final ratio completed. On a FR1 schedule, the estrous cycle had no effect on the rate of drug intake. On a PR schedule, female rats reached higher breaking points during estrus than during other stages of the estrous cycle. Furthermore, female rats displayed higher breaking points than male rats. It appears that the estrous cycle influences an animal's motivation to self-administer cocaine.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    ISSN: 1434-601X
    Schlagwort(e): 23.90.+ w ; 23.90.+ e ; 27.70.+ q
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract The fusion reaction74Se+106Cd→180Pb* at a compound nucleus excitation energy Ex ≃ 40 MeV, has been used in a search for the decay of the unknown nucleus177Tl. Evaporation residues were velocity and mass analysed prior to implantation into a position sensitive silicon surface barrier detector. No evidence was discovered for the proton or alpha-decay of177Tl for a cross-section 〉 10 − 5+10 nb. This indicates either that177Tl decays too rapidly (t1/2 〈 1 μs) by proton emission for the decay to be detected, or that177Tl is produced with a cross-section less than the limit established in the present experiment. The following nuclear decay half-lives were measured with improved accuracy;177Hg (t1/2 = 130±5 ms),178Hg (t1/2=250±25 ms) and177Au (t1/2=1180±70 ms). The experiment also provided the first direct confirmation of the correct mass assignment of the alpha-decay, Eα=6.26 MeV, to the decay of176Au. Two additional halflife measurements of proton-rich Osmium isotopes are also presented from a previous similar experiment;165Os (t1/2=73±8 ms) and166Os (t1/2 = 194±17 ms).
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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