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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Diabetologia 7 (1971), S. 339-348 
    ISSN: 1432-0428
    Keywords: Autoradiography ; 5-hydroxytryptamine ; 5-hydroxytryptophan ; monoamine oxidase inhibition ; mouse ; pancreatic islets ; reserpine ; ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé En appliquant la technique autoradiographique, on a étudié la distribution cellulaire et subcellulaire de la radioactivité dans les îlots pancréatiques de la souris après une injection intra-veineuse de3H-5-hydroxytryptophane. Des grains d'argent autoradiographiques dont la plupart représentent probablement de la 5-hydroxytryptamine qui s'est formée à partir du précurseur marqué, sont apparus sur les cellules A2 et B, tandis que très peu de grains ont été trouvés sur les cellules A1 à chacun des examens (entre 20 min et 16 h) et de même après l'inhibition de la monoamine-oxidase. L'analyse quantitative des coupes autoradiographiques a révélé que la concentration de grains d'argent sur les granules spécifiques des cellules A2 et B était 5 à 10 fois plus élevée que sur les parties restantes de ces cellules. Sur les cellules A2 le nombre le plus élevé de grains a été noté 20 min après l'injection du marqueur et sur les cellules B une heure après cette injection. Au bout de 8 h, il n'apparaissait que très peu de grains d'argent sur les cellules des îlots, et plus aucun au bout de 16 h. L'inhibition de la monoamine-oxidase a provoqué une augmentation de la rétention de marqueur sur les cellules des îlots, plus prononcée sur les cellules A2. Un traitement préalable à la réserpine a supprimé cette réaction autoradiographique.
    Abstract: Zusammenfassung Mit Hilfe der Technik der Autoradiographie wurde die zelluläre und subzelluläre Verteilung der Radioaktivität nach intravenöser Applikation von3H-5-Hydroxytryptophan in den Pankreasinseln der Maus untersucht. Die autoradiographischen Silberkörner, welche zumeist 5-Hydroxytryptamin darstellen, das aus der radioaktiven Ausgangssubstanz gebildet worden war, erschienen über den A2 und B-Zellen, während nach jedem untersuchten Zeitintervall (20 min–16 Std) auch wenn die Monoamino-Oxidase gehemmt wurde, nur sehr wenige Körner über den A1-Zellen erschienen. Quantitative Untersuchungen der Autoradiographieschnitte zeigten, daß die Konzentration der Silberkörner über den spezifischen Granula der A2-Zellen und der B-Zellen etwa 5–10 mal höher als über den restlichen Teilen der Zellen war. In den A2-Zellen wurde die höchste Körnerkonzentration nach 20 min, in den B-Zellen 1 Std nach Injektion der markierten Substanz festgestellt. Nach 8 Std zeigten sich nur wenige, nach 16 Std keine Silberkörner mehr über den Inselzellen. Die Hemmung der Monoamino-Oxidase verursachte eine vermehrte Anreicherung von Radioaktivität über den Inselzellen, am meisten über den A2-Zellen. Eine Vorbehandlung mit Reserpin verhinderte die autoradiographische Darstellung.
    Notes: Summary By application of autoradiographic technique the cellular and subcellular distribution of radio-activity in mouse pancreatic islets was investigated following intravenous administration of3H-5-hydroxytryptophan. Autoradiographic silver grains, most of which probably represent 5-hydroxytryptamine formed from the labelled precursor, appeared over A2 and B cells, whereas very few grains were recorded over A1 cells at any time investigated (20 min–16 hours) and also when monoamine oxidase was inhibited. Quantitative analysis of autoradiographic sections revealed that the concentration of silver grains over the specific granules of A2 and B cells was 5–10 times higher than over the remaining parts of these cells. In A2 cells the highest grain count was recorded at 20 minutes, in B cells at 1 hour after the injection of label. After 8 hours very few, and after 16 hours no silver grains appeared over islet cells. Inhibition of monoamine oxidase caused an increased retention of label over islet cells, most pronounced over A2 cells. Pretreatment with reserpine abolished the autoradiographic reaction.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-2072
    Keywords: Key words Acoustic startle response ; Prepulse inhibition ; Sensorimotor gating ; Schizophrenia ; Medial geniculate body ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Prepulse inhibition of acoustic startle is the normal reduction in startle response to an intense auditory stimulus when this stimulus is immediately preceded by a weaker prestimulus. Previous studies have shown that several neuroanatomical structures and pathways in the brain are involved in the modulation of prepulse inhibition. In the present study, the functional importance of the medial geniculate body (MG) in the modulation of prepulse inhibition was investigated. To this end, in vivo brain microdialysis probes were used to infuse drugs locally into the MG of awake, freely moving rats simultaneously with startle response and prepulse inhibition measurements in the same animals. Intrageniculate infusion of the sodium channel blocker, tetrodotoxin, significantly reduced prepulse inhibition without affecting baseline startle amplitude. A similar effect was obtained after intrageniculate infusion of the GABAB receptor agonist, baclofen. In addition, intrageniculate infusion of muscimol, an agonist at the GABAA receptor complex, reduced prepulse inhibition, although this effect was obtained at a higher concentration of the drug compared to that of baclofen. These studies suggest that the MG is involved in the modulation of prepulse inhibition and that auditory signals relayed via the MG may be subjected to inhibitory control at this level, involving GABA neurotransmission.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 102 (1990), S. 171-174 
    ISSN: 1432-2072
    Keywords: Discrimination ; Avoidance ; PCP ; Dopamine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were trained to performed an aversely motivated discriminative task in a shuttle-box. The administration of phencyclidine (PCP), 2 mg kg−1 SC at −20 min, produced disruption of discriminative performance and an increase in intertrial crosses. There were no changes in avoidance performance or in avoidance latency. Pretreatment with haloperidol, 0.1 or 0.2 mg kg−1 SC at −40 min, or remoxipride 8 mg kg−1 IP at −30 min, did not antagonize the PCP-induced disruption of discriminative performance, nor was the PCP-induced increase in number of intertrial crosses antagonized. In fact, there appeared to be a further increase in intertrial crosses, above PCP levels, by haloperidol treatment and this effect was statistically significant after remoxipride treatment. The present results, together with previous observations that alsod-amphetamine disrupts discriminative conditioned avoidance behavior, suggest the possibility that this model could be used in the search for new, non-dopaminergic, antipsychotic drugs.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 27 (1901), S. 209-253 
    ISSN: 0863-1778
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-0878
    Keywords: Endostyle ; Autoradiography ; Cytochemistry ; Iodination ; Protothyroid ; Salpa fusiformis, Thalia democratica, Dolioletta gegenbauri, Doliolum nationalis (Tunicata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The protothyroid region in the endostyles of four species of tunicates was examined by means of autoradiography and cytochemistry, at both the light and electronmicroscopic levels. To reveal the primary binding site for iodine, autoradiography was carried out on endostylar tissue from animals that had been incubated with high activity 125I- over a short period of time. The specific iodine binding enzyme, a peroxidase, was traced by its reaction with DAB. In accordance with previous findings, the iodinebinding cells proved to be the same as those containing the peroxidase. There were also strong indications of a secondary uptake of iodinated compounds and subsequent release into the body fluid. Together with the ultrastructural features, the data provided strong evidence indicating that these cells constitute a protothyroid region, which partly functions as an endocrine organ, possibly homologous with the vertebrate thyroid gland. Since the number of zones varied between the species, the numeration of the protothyroid region also varied. However, in all the examined endostyles, the protothyroid region was seen to be situated dorsolaterally to the glandular regions of the endostyle concerned with food capture.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A specific assay is described for the confirmatory identification of danofloxacin residues in edible tissues of cattle and chicken. The assay utilizes on-line microbore high-performance liquid chromatography and pneumatically assisted electrospray tandem mass spectrometry (MS/MS). Collision-induced dissociation of the danofloxacin protonated molecule results in two significant daughter ions. Monitoring both ions provides the specificity required for this confirmatory assay. Optimum electrospray and MS/MS operating conditions permitted the specific monitoring of danofloxacin and the confirmation of its residues in chicken and cattle liver extracts down to 50 ppb. The analysis of control liver or the commercially available antibacterial quinolones enrofloxacin and its metabolite ciprofloxacin gave no response under the assay conditions. The ratios of the two daughter ions were similar for danofloxacin standard solutions, fortified tissues and incurred tissues.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 31 (1991), S. 1057-1063 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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: An attempt was made to improve the properties of filament wound glass fiber-epoxy composites by addition of carboxyl-terminated-butadiene-acrylonitrile (CTBN)-rubber to the matrix. The interlaminar GIc of unidirectional glass fiber-epoxy increased significantly with CTBN addition whereas the flexural strength decreased. The weepage stress in hoop loading of ±50 degree angle-ply pipes was higher for unmodified as compared with 10 phr CTBN-modified epoxy matrix pipes. However, the strain at weepage and the stress and strain at nonlinearity were higher for the pipes based on toughened epoxy. The reason for the lower weepage stress is that, although the toughened matrix pipes show higher resistance to cracking, their stiffness is lower. The addition of small amounts of CTBN-rubber (about 5 percent by weight is suggested) to the present epoxy matrix for filament winding can be done with only a minor increase in viscosity. This is a way of toughness enhancement for applications where the matrix stiffness reduction and increased moisture absorption are of minor importance.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 5 (1963), S. 147-165 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A number of factors was found to affect the cup plate assay for lysine with Streptococcus faecalis ATCC 6057. Hydroxylysine, aspartic acid, and Tween 80 were found to be among the essential components of the assay medium. Removal of any of these three components produced diffuse growth zones or otherwise unsatisfactory plates. The inclusion of asparagine and additional dipotassium phosphate to the medium was found to be advantageous but not an absolute requirement. It was important not to autoclave the hydroxylysine and the additional dipotassium phosphate together with the rest of the assay medium, but to add these components to the sterilized medium immediately before pouring the plates. With certain concentrations of hydroxylysine in the medium, the addition of L-glutamine was found to potentiate the effect of hydroxylysine and thereby improve the lysine plates. The effect of graded amounts of the above mentioned medium components and of the pH of the assay medium was also studied. Increasing the sterilization time of the medium from 5 to 10 min. at 120°C. improved the readability of the lysine plates and led to more easily reproducible results. Factors influencing the preparation of the inoculum for the lysine plates were also studied: the age of the stab culture, the amount of inoculum used per plate, and the influence of the nature of the suspension medium used for washing the inoculum.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 4 (1962), S. 23-36 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The ability of a number of Ustilago species, especially Ustilago maydis (DC.) Cda., to produce lysine and threonine was investigated. The organisms were grown in shake flasks or in 10-l. fermentors. Lysine and threonine were found to be excreted into the medium both in the free and bound form. The bound amino acids could be released by acid hydrolysis or by enzymes from autolyzed cells. The optimal conditions for the release by autolysis were, in the case of Ustilago maydis (DC.) Cda., pH 4.3 and 45°C. An enzyme that could liberate lysine from the bound form(s) occurring in the broth was extracted from cells of Ustilago maydis (DC.) Cda. It exhibited an apparent pH optimum near 4.0. The effect of pH and temperature during the growth phase on the yield of lysine and threonine was studied in 10-l. fermentations.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The ability of Ustilago maydis (DC.) Cda. to grow and to produce lysine and threonine was investigated in shake flask cultures. Growth and production of lysine and threonine increased markedly when aeration was increased. The optimal ratio of glucose to diammonium phosphate in the medium seemed to be approximately 10:1. Ammonium phosphate, ammonium sulfate, ammonium chloride, ammonium nitrate, sodium nitrate, urea, aspartic acid, glutamic acid, and glycine were readily used as nitrogen sources. Growth and amino acid production was poor on ammonium carbonate, ammonium acetate, ammonium citrate, trimethylamine, and betaine.U. maydis (DC.) Cda. was found to grow on a number of different carbohydrates. Besides D-glucose the organism could utilize D-mannose, D-galactose, D-fructose, L-arabinose, D-xylose, D-ribose, sucrose, maltose, and the polyalcoholes D-sorbitol, D-mannitol, and i-inositol. Pectin, dextrin, and corn starch treated with α-amylase could also be used but not untreated corn starch or lactose, cellobiose, D-sedoheptulose, glycerol, or D-glucosamine. The formation of lysine and threonine was better with disaccharides and hexoses than with pentoses.No specific effects on the formation of lysine and threonine could be observed from changes in the concentration of calcium, sodium, potassium, magnesium, zinc, iron, copper, manganese, cobalt, or molybdenum. The requirement of metal ions for growth is discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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