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  • 1
    Digitale Medien
    Digitale Medien
    Contribution of histamine and prostanoids to bronchoconstriction provoked by inhaled bradykinin in atopic asthma (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 45 (1990), S. 0 
    Details
    ISSN: 1398-9995
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Bradykinin, a nonapeptide cleavage product of high molecular weight kininogen, is a potent bronchoconstrictor agonist in asthma; however, its mechanism of action is not known. Since bradykinin has been shown to stimulate mediator release from mast cells and augment the release of prostanoids, we have examined the effect of a selective histamine H1 receptor antagonist, terfenadine and a potent cyclooxygenase inhibitor, flurbiprofen on bronchoconstriction provoked by inhaled bradykinin in asthma. As a bronchial provocation procedure bradykinin challenge was repeatable to within 1 doubling dilution. In nine atopic asthmatic subjects, terfenadine 180 mg, when compared to placebo, increased the geometric mean provocation concentration of inhaled agonist required to reduce FEV, by 20% of baseline (PC20) from 0.7 to 〉 22.9 mg/ml for histamine (P 〈 0.01) and 0.3 to 0.5 mg/ml for bradykinin (P 〈 0.01). In a further nine atopic asthmatics, flurbiprofen 150 mg when compared to placebo produced a small but significant protection of the airways against bradykinin. geometric mean PC20 increasing from 0.40 to 0.79 mg/ml (P 〈 0.05). We conclude that bradykinin is a potent bronchoconstrictor agonist in asthma, being approximately 9.5 times more potent than histamine in molar terms. Pharmacological intervention with terfenadine and flurbiprofen led to a significant protection of the airways against the constrictor effect of bradykinin but the effect in each case was small. Thus, while histamine and prostanoids may contribute as mediators of bradykinin-induced bronchoconstriction, they are unlikely to account for the majority of the response.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1398-9995.1990.tb00480.x
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  • 2
    Digitale Medien
    Digitale Medien
    Nedocromil sodium is more potent than sodium cromoglycate against AMP-induced bronchoconstriction in atopic asthmatic subjects (1989)
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 19 (1989), S. 0 
    Details
    ISSN: 1365-2222
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Nedocromil sodium is a new chemical entity which shows similar properties to sodium cromoglycate (SCG) and in addition exhibits a preferential activity in stabilizing mucosal mast cells. We have compared the effect of inhalation of nebulized placebo, SCG and nedocromil sodium on the bronchoconstrictor response to inhaled adenosine monophosphate (AMP) in eight atopic asthmatic subjects aged 25 yr (range 21–32 yr). The geometric mean provocation doses of AMP required to produce a 20% decrease in FEV1 (PD20 FEV1) and a 40% decrease in V˙max30 (PD40 V˙max30) following placebo were 4.9 (0.3–14.2) and 1.8 (0.1–8.4) μmol respectively. Prior inhalation of both SCG and nedocromil sodium significantly inhibited the bronchoconstrictor response to AMP with PD20FEV1s of 36.6 (4.0–132.7) and 134 (12.4–560), and PD40 V˙max30 values of 20.5 (1.4–110) and 101.6 (5–560) μmol respectively (P〈0.001). Nedocromil sodium was 3.9 (FEV1) and 8.0 (Vmax30) times more potent than SCG (P〈0.001). In conclusion, both drugs inhibit the bronchoconstrictor response to inhaled AMP, and nedocromil is at least 4–8 times more potent than SCG.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2222.1989.tb02385.x
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  • 3
    Digitale Medien
    Digitale Medien
    The effect of histamine-H1 receptor antagonism with terfenadine on concentration-related AMP-induced bronchoconstriction in asthma (1989)
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 19 (1989), S. 0 
    Details
    ISSN: 1365-2222
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Selective histamine-H1 receptor antagonists inhibit adenosine 5′-monophosphate (AMP)-induced bronchoconstriction by 〉 80% when expressed as a percentage inhibition of the FEV1 time–response curve following inhalation of the provocation concentration of AMP required to produce a 20% decrease in FEV1 from baseline (PC20). To investigate this further we have determined that, in eight mild atopic asthmatic subjects, terfenadine (180 mg), administered 3 hr pre-challenge, increases the geometric mean PC20 for histamine from 0.4 (range 0.03–3) mg/ml after placebo, to 20.2 (range 0.6–64) mg/ml following active treatment (P〈0.0001). For AMP, the PC20 increased from 9.3 (range 1.0–113.3) mg/ml after placebo, to 150.2 (range 32.1–1177.7) mg/ml with terfenadine (P〈0.0001). This 16.2-fold (range, 5.5–47.9) displacement to the right of the AMP concentration–response curve by a selective histamine-H1 receptor antagonist emphasizes the central role of histamine in the airways response to this nucleotide.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2222.1989.tb02406.x
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  • 4
    facet.materialart.
    Unbekannt
    Handicrafts in the Soviet Union (1943)
    London : Periodicals Archive Online (PAO)
    Africa. 14:4 (1943/1944) 209 
    Details
    ISSN: 0001-9720
    Thema: Ethnologie , Politikwissenschaft , Sociologie
    URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pao:&rft_dat=xri:pao:article:4011-1943-014-04-000009
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  • 5
    Digitale Medien
    Digitale Medien
    A Difference in the Physiology of the Large Intestine between European and Indigenous Cattle in the Tropics (1957)
    [s.l.] : Nature Publishing Group
    Nature 180 (1957), S. 552-553 
    Details
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] It had already been found that there was a difference between the faeces of the two animals when E. Brauwer and E. J. v. Weerden1 published their investigations on the osmotic pressure of the gut contents of grades. We then determined freezing-point depressions and dry matters of the contents of ...
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1038/180552a0
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  • 6
    Digitale Medien
    Digitale Medien
    Organ weights, liver constituents, and serum components in growing chicks fed ochratoxin A (1989)
    Springer
    Archives of environmental contamination and toxicology 18 (1989), S. 404-410 
    Details
    ISSN: 1432-0703
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Energietechnik , Medizin
    Notizen: Abstract Chicks were fed diets containing 0, 1, 5 and 10 mg/kg ochratoxin A (OA) over a four-week period to study the effects of OA on growth, weight of internal organs, liver RNA, DNA, protein, and glycogen and serum enzymes. Ochratoxin A depressed the rate of growth and relative weight of the bursa of Fabricius, and increased the relative weights of the liver, kidney, pancreas, and various sections of the gastrointestinal tract, but had no effect on the heart and spleen. Concentrations of liver RNA, DNA and protein were decreased while glycogen was increased. Serum alkaline phosphatase and γ-glutamyl transferase activities, and uric acid and creatinine concentrations were elevated while serum proteins, albumin, phosphorus, potassium, and cholesterol were depressed. The effects of OA were time- and dose-dependent.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01062365
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  • 7
    Digitale Medien
    Digitale Medien
    Enhanced stimulus-reward learning by intra-amygdala administration of a D3 dopamine receptor agonist (1997)
    Springer
    Psychopharmacology 133 (1997), S. 240-248 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Key words Stimulus-reward learning ; Discriminative approach ; Dopamine ; Amygdala ; SKF-38393 ; Quinpirole ; 7-OH-DPAT ; D3 receptor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The amygdala is considered to be a critical neural substrate underlying the formation of stimulus-reward associations, and is known to receive substantial innervation from dopaminergic neurons located within the ventral mesencephalon. However, relat- ively little is known about the function of the mesoamygdaloid dopamine projection in stimulus-reward learning. Recently, we have found post-session intra-amygdala microinjections of d-amphetamine to enhance appetitive Pavlovian conditioning as assessed in a discriminative approach task. In the present study, we have examined the effects of dopamine receptor agonists possessing relative selectivity for the D1, D2 and D3 receptor subtypes in order to examine more fully the role of the mesoamygdaloid dopamine projection in stimulus-reward learning. Thus, subjects were trained to associate an initially neutral stimulus (CS+) with 10% sucrose reward (US). A second, control stimulus (CS−) was also presented but never paired with sucrose reward. In order to measure specifically the conditioned response to CS+/CS− presentation, responding during CS and US presentations was measured separately. Immediately following each training session, subjects received bilateral intra-amygdala infusion of 0.1, 1 or 10 nmol/side of SKF-38393, quinpirole or 7-OH-DPAT. Infusions of SKF-38393 or quinpirole were without effect on CS+ approach. However, post-session intra-amygdala infusions of 7-OH-DPAT enhanced selectively CS+ approach in a dose-dependent fashion. No dose of any drug affected CS−approach, US behaviours, or measures of extraneous behaviour. Subsequent acquisition of a novel conditioned instrumental response was also unaffected. Thus, the present data indicate a selective involvement of the D3 dopamine receptor subtype in the modulation of stimulus-reward learning by the mesoamygdaloid dopamine projection.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002130050397
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  • 8
    Digitale Medien
    Digitale Medien
    Amygdala and hippocampus control dissociable aspects of drug-associated conditioned rewards (1997)
    Springer
    Psychopharmacology 131 (1997), S. 187-195 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Key words Intracranial self-administration ; Conditioned reward ; d-Amphetamine ; CNQX ; Nucleus accumbens ; Ventral subiculum ; Basolateral area of the amygdala
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Limbic innervation of the nucleus accumbens via the ventral subiculum/hippocampus and basolateral area of the amygdala has been shown to determine dissociable aspects of behaviour controlled by stimuli associated with natural rewards. However, the respective contributions of the ventral subiculum and amygdala to behaviour governed by drug-associated stimuli remain to be determined. Experiments consisted of two phases: drug-stimulus training, and subsequent stimulus-only testing. Initial training sessions were of two alternating forms. During drug sessions, responding upon one lever resulted in an infusion of 1 μg d-amphetamine into the nucleus accumbens, whilst during saline sessions d-amphetamine was replaced with saline. Each infusion (drug or saline) was preceded with either a light, or tone. Responding upon a control lever had no programmed consequences. Following training, the levers were retracted, and instead two novel vertical bars were extended from the chamber ceiling. Movement of one bar produced the drug-associated stimulus, whilst the alternative bar produced the saline-associated stimulus. Infusions of the AMPA receptor antagonist CNQX into the ventral subiculum or basolateral area of the amygdala (0, 0.2, 2.0 nmol) were made immediately before the start of each session. Intra-basolateral area of the amygdala CNQX reduced responding upon the drug-associated stimulus bar, but at the same time increased responding upon the saline-associated stimulus bar. By contrast, intra-ventral subiculum CNQX reduced drug-associated stimulus responding selectively. Neither manipulation affected levels of activity within the operant chamber extraneous to the bar-pushing response. Hence, the basolateral area of the amygdala appeared to have determined the degree of discriminative control exerted over behaviour by the drug-associated stimulus, whilst the ventral subiculum is suggested to have determined the efficacy of the conditioned reward.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002130050283
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  • 9
    Digitale Medien
    Digitale Medien
    Enhanced conditioned inhibition following repeated pretreatment with d-amphetamine (1999)
    Springer
    Psychopharmacology 142 (1999), S. 120-131 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Key words Sensitisation ; d-Amphetamine ; Conditioned inhibition ; Amygdala ; Nucleus accumbens ; Reward ; Conditioning
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We have shown that prior repeated exposure to d-amphetamine facilitates appetitive Pavlovian conditioning. However, animals sensitised in this manner also show elevated levels of stimulated activity. To investigate whether enhanced conditioning was dependent upon increased activity, a conditioned inhibition task was employed in the present study. Rats received d-amphetamine (2 mg/kg, IP) or vehicle once per day for 7 days. After a 7-day drug-free period, an activity assay confirmed that repeated d-amphetamine treatment markedly elevated the locomotor response to a subsequent challenge with 0.5 mg/kg d-amphetamine. Conditioning began 6 days later. In phase 1, stimulus A+ (light or tone) immediately preceded sucrose availability (excitatory conditioning). In phase 2, sucrose again was presented after A+ alone, but not after presentation of a compound of A+ with a second stimulus (AB−). Sensitisation enhanced the acquisition of conditioned approach behaviour to the excitatory stimulus A+ in phase 1. Furthermore, acquisition of conditioned inhibition to the stimulus compound, AB−, was also facilitated. Thus, sensitised rats showed reduced levels of responding to the stimulus compound far sooner than controls. Finally, a retardation test was carried out in stage 3, in which the inhibitory stimulus B- was paired alone with sucrose reward. Sensitised rats initially showed retarded acquisition of excitatory conditioned responding relative to controls, suggesting that B possessed stronger inhibitory associations in these animals. However, sensitised animals again exhibited higher levels of responding in later sessions, consistent with the enhanced excitatory conditioning shown in phase 1. These findings suggest that prior repeated d-amphetamine enhanced the acquisition of inhibitory and excitatory Pavlovian associations; a propensity not readily attributable to stimulated locomotor hyperactivity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002130050870
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  • 10
    Digitale Medien
    Digitale Medien
    Repeated d-amphetamine enhances stimulated mesoamygdaloid dopamine transmission (1997)
    Springer
    Psychopharmacology 132 (1997), S. 247-254 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Key words Dopamine ; Sensitisation ; Microdialysis ; Amygdala ; Nucleus accumbens
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The mesoaccumbens dopamine pathway exhibits an enhanced dopaminergic response to a challenge injection of d-amphetamine or cocaine after repeated intermittent exposure to that drug. Much research has focused on the potential role of this sensitised response in the enhanced propensity of drug-associated stimuli to elicit relapse. However, the amygdala is acknowledged to play a critical role in stimulus-reward learning, and recent work suggests that the mesoamygdaloid dopamine pathway exerts a significant influence upon amygdala function. In the present study, rats were administered d-amphetamine (1 mg/kg, IP) or vehicle once per day, for 14 days. After 11 untreated days, a locomotor assay showed that prior repeated administration of d-amphetamine led to a markedly enhanced locomotor response to 0.5 mg/kg d-amphetamine. There was no effect of d-amphetamine pretreatment upon the response to a novel environment, or to injection with vehicle. Following a total of 14 days in the home cage, subjects were implanted with microdialysis probes within the amygdala, and for comparison also within the nucleus accumbens. Baseline and d-amphetamine-stimulated (0.5 mg/kg) levels of extracellular dopamine were assessed for each brain region. Results showed that baseline levels of dopamine were very similar in sensitised and control animals. By contrast, prior treatment with d-amphetamine enhanced dopamine overflow in response to a challenge with d-amphetamine both in the nucleus accumbens and amygdala. These results indicate that changes in the pattern of dopamine transmission both in the nucleus accumbens, and the amygdala, accompany the behavioural sensitisation observed after repeated exposure to d-amphetamine. Hence, an enhanced propensity of drug-associated stimuli to elicit relapse may not depend solely upon changes relating to the mesoaccumbens dopamine projection.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002130050342
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