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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
N-arylsubstituted-1-aryl-3,4-diphenyl-5-pyrazole amines with analgesic and antiarrhythmic properties.
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Effects of the selective adenosine A1 receptor agonist 5 '-chloro-5 '-deoxy-N6-(2-endo-norbornyl) adenosine on nociception in mice
No full textBackground. To investigate the analgesic effect of 5’-chloro-5’-deoxy-N6-(2-endo-norbornyl)-adenosine (5’Cl5’d-(±)-ENBA), a very selective agonist with subnanomolar affinity for the human A1 adenosine receptor (A1AR), the formalin test was applied in freely moving mice. Methods. The formalin test-induced pain is a widely used animal model of persistent pain. Nociceptive responses are divided into an early, short lasting first phase (0-7 min) caused by a primary afferent discharge produced by the stimulus, followed by a quiescent period and a second, prolonged phase (15-60 min) of tonic pain. The total time of the nociceptive response was measured every 5 min and expressed as the total time of the responses in min (mean SEM). Recording of nociceptive behaviour commenced immediately after the formalin injection and was continued for 60 min. Results. Systematic administration of 5’Cl5’d-(±)-ENBA (1-2 mg/Kg, i.p.), 10 min before formalin reduced the late nocifensive behaviour induced by formalin in a dose-dipendent manner. The higher dose 5’Cl5’d-(±)-ENBA used reduced both the early and the late phases of the formalin test, and this was prevented by the DPCPX (3 mg/Kg, i.p.), a selective A1 receptor antagonist. Conclusion. These data further evidence that the adenosine A1 receptor stimulation results effective in reverting formalin-induced nocifensive behaviour in mice and suggest that the presence of adenosine receptors within the endogenous antinociceptive pathway may play a critical role in pain modulation. Moreover, it was demonstrated that the substitution of 5’-OH group with a chlorine in adenosine derivatives is not detrimental for the antinociceptive effect mediated by A1AR
2-Aryl-6-methyl-3-phenylamino-6,7-dihydropyrano[4,3-c]pyrazol-4(2H)-ones with analgesic activity.
No full textMetabotropic glutamate receptors modulate periaqueductal grey descending analgesic system
No full textEvidence for non-adrenergic non-cholinergic contractile responses in bovine and swine trachea
No full textNon-adrenergic non-cholinergic (NANC) contraction of airway smooth muscle has been observed in some but not all animal species. The aim of this study was to investigate the NANC-contractile responses in bovine and swine trachea. Proximal and distal bovine and swine trachea were cut in strips and placed in 10 ml organ baths equilibrated in Krebs Henseleit (KH) solution and electrically stimulated (10 sec, 60 V, 2 ms, 4, 10 and 30 Hz). Contractile frequency response curves performed in the presence of the muscarinic antagonist, atropine (100 mM), the angiotensin converting enzyme inhibitor, captopril (1 microM) and the neutral endopeptidase inhibitor, thiorphan (1 microM), added 30 min prior to electrical field stimulation (EFS). In some tissues, incubated with atropine thiorphan and captopril, were also evaluated the effects of a pretreatment with capsaicin (10 microM) or a selective NK1 receptor antagonist, SR 14033 (100 nM) added to the baths 30 min prior to EFS. Bovine and swine proximal and distal tracheal preparations contracted in a frequency-dependent manner to EFS (4, 10 and 30 Hz). Some experiments were also performed with substance P (0.1 nM to 1 microM) in absence or in presence of SR 14033 (10 nM or 100 nM). At the maximum frequency tested (30 Hz), the contractile response elicited in bovine proximal and distal preparations was 194.5 +/- 17.1% and 229.7 +/- 24.1%, of ACh (100 microM), respectively. Similarly, the contractile response elicited by EFS (30 Hz) in swine proximal and distal preparations was 187.2 +/- 12.1% and 181.6 +/- 9.2% of ACh (100 microM), respectively. In tissues incubated with atropine, a significant decrease in smooth muscle sensitivity to EFS was observed (P < 0.05). When tissues were pretreated with captopril and thiorphan, a significant increase in the contractile response to EFS (30 Hz) was observed in all tested tissue preparations (bovine, proximal 210.1 +/- 14.4%, distal 264.3 +/- 16.2%; swine, proximal 199.3 +/- 14.9%, distal 206.3 +/- 16.2%, P < 0.05). In the presence of atropine, captopril and thiorphan a significant increase in the contractile response was observed in bovine and swine distal preparations compared with tissues incubated with atropine only (P < 0.05). These effects were antagonized by a pretreatment with a selective NK1 receptor antagonist, SR 14033. A pretreatment with capsaicin statistically (P < 0.05) enhanced EFS-induced contraction in all tested preparations respect to tissues incubated with atropine, thiorphan and captopril. Substance P induced a concentration dependent contraction of bovine and swine isolated tracheal preparations which was antagonized by a pretreatment with a selective NK1 receptor antagonist, SR 14033. No significant difference in the contractile potency (EC50) nor in maximum response (Emax) was observed to exogenously administered substance P between proximal and distal tracheal preparations. These data suggest that NANC contractile responses are present in bovine and swine trachea and are more evident in distal airways.[...
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