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  • 1
    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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  • 2
    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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  • 3
    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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  • 4
    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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  • 5
    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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  • 6
    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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  • 7
    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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  • 8
    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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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 5 (1963), S. 131-146 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A sensitive cup plate assay method for lysine on large plates using S. faecalis ATCC 6057 as the test organism is described in detail. Well-defined zones of dense growth were obtained in a rectilinear dose - response range from 5 to 3000 μg. of L-lysine/ml. Comparative assays on twelve different samples were carried out using the turbidimetric tube assay method with Leuc. mesenteroides ATCC 8042 and the cup plate method with S. faecalis ATCC 6057. Good agreement between the two assay methods was obtained for five samples. For the remaining seven samples the tube assay values were appreciably higher than those obtained by the plate method. This discrepancy is discussed. Pure lysine added to various sample extracts could be quantitatively recovered. The specificity of the lysine requirement of S. faecalis ATCC 6057 in the plate assay was also investigated. Under certain experimental conditions, a weak and variable response was obtained with D-lysine and the polyamines cadaverine, spermine, and spermidine. There was generally no difficulty in distinguishing the D-lysine and polyamine growth zones from the L-lysine growth zones. This growth effect of D-lysine and polyamines could be diminished and even completely abolished by increasing the DL-hydroxylysine hydrochloride level in the plate medium. The lysine peptides glycyl-L-lysine and L-lysylglycine gave excellent growth zones of the same appearance as those produced by L-lysine. The activity of these two peptides in cup tests were on a molar basis about 70% of that of L-lysine.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 128 (1972), S. 406-425 
    ISSN: 1432-0878
    Keywords: Parafollicular Cells ; Rat ; Normalcalcemia ; Vitamin D2 ; Electronmicroscopy ; Histochemical fluorescence method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Thyroid parafollicular cells of normocalcemic and vitamin D2-treated rats were investigated by electron microscopy and with the histochemical fluorescence technique of Hillarp and Falck. Administration of high doses of vitamin D2 caused hypercalcemia and an extensive degranulation of the parafollicular cells. The formation and storage of monoamines in granulated and degranulated parafollicular cells was investigated by fluorescence microscopy after injection of monoamine precursors (DOPA, 5-HTP), alone or in combination with Ro 4-4602, nialamide or reserpine. No fluorescence was observed in parafollicular cells of untreated rats. l-DOPA and l-5-HTP (but not the corresponding D-amino acids) were taken up by a process closely linked to the decarboxylation of the amino acids to the corresponding amines (dopamine and 5-hydroxytryptamine). Treatment with vitamin D2 did not seem to affect the formation of amines in the parafollicular cells or the formation and storage of amines in other cell systems investigated. The amine itself (dopamine) was not taken up by the parafollicular cells. In normocalcemic rats, the amine formed was retained in the cytoplasm of the parafollicular cells by a partially reserpine-resistant mechanism. The storage of amines is concluded to occur in association with the calcitonin-containing granules. In parafollicular cells of vitamin D2-treated rats, a certain amount of amine was bound in the cytoplasm in the absence of typical granules. As a considerable amount of calcitonin is known to remain in the thyroid of vitamin D2-treated rats, the present observations may indicate an association between the amine and the polypeptide hormone calcitonin, whether the latter is confined to typical granules or not.
    Type of Medium: Electronic Resource
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