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| 2. |
- Bergendorff, O., et al.
(author)
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Screening of some European medicinal plants for spasmolytic activity on isolated guinea-pig trachea
- 1995
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In: International Journal of Pharmacognosy. - 0925-1618. ; 33:4, s. 356-358
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Journal article (peer-reviewed)abstract
- Eight European plants, used traditionally against diseases of the respiratory system, have been assayed for in vitro spasmolytic activity on guinea-pig trachea. The plants were collected or cultivated in the south of Sweden, and both water and 67% methanol extracts of the parts reported to be used in the traditional medicine were prepared and assayed. Five of the species did not show any significant activity at concentrations up to 0.6 mg extract per ml organ bath, the methanol extracts of 2 species (Glechoma hederacea and Hyssopus officinale) showed weak activity, while 0.6 mg/ml of the methanol extract of the aerial parts of Artemisia abrotanum relaxed the tone induced by 0.1 μmol/l carbachol almost (80%) as effectively as 2.2 mmol/l terbutaline.
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| 3. |
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| 4. |
- Andersson, Malte, 1941, et al.
(author)
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Female sociality and kin discrimination in brood parasitism: unrelated females fight over egg laying
- 2015
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In: Behavioral Ecology. - : Oxford University Press (OUP). - 1045-2249 .- 1465-7279. ; 26:3, s. 755-762
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Journal article (peer-reviewed)abstract
- In conspecific brood parasitism, some females ("parasites") lay eggs in nests of other females of the same species ("hosts"). This reproductive tactic is particularly common in waterfowl, in which studies suggest that parasites are often related to the host. Here, we test the hypothesis that hosts may discriminate and reject unrelated parasites. Based on observations and >4100 h of digital video film, we analyze behavioral interactions at 65 nests of High Arctic common eiders during the laying sequence. We also estimate parasitism and host-parasite relatedness by albumen fingerprinting of 975 eggs from 232 nests. Among the video-filmed nests in which interactions were recorded during the egg-laying period, 11 had eggs from 2 females. At 8 of these 11 nests, there was overt female aggression and significantly lower host-parasite relatedness (mean coefficient of relationship r = -0.40) than in the nests with tolerant or no interactions (r = 0.91). The results demonstrate active female kin discrimination in common eiders, used against nonrelatives that try to lay eggs in the nest. Other females trying to access the nest were often prevented from doing so: in 65% of 34 such attempts, the sitting female rejected the intruder. Brood "parasitism" in eiders and other waterfowl is complex, ranging from violent female conflict and parasitic exploitation of the host's parental care to nest takeover and potential kin selection favoring acceptance of related parasites. These and other aspects of female sociality in eiders are discussed; in some respects, they may resemble certain long-lived matriarchal mammals.
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| 5. |
- Grundemar, L, et al.
(author)
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Neuropeptide Y : prejunctional inhibition of vagally induced contractions in the guinea pig trachea
- 1988
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In: Regulatory Peptides. - : Elsevier BV. - 0167-0115. ; 23:3, s. 309-313
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Journal article (peer-reviewed)abstract
- The effects of neuropeptide Y (NPY) on the contractile response to vagus nerve stimulation at different frequencies was studied in an isolated tracheal tube preparation from guinea pig. NPY had no effect on basal smooth muscle tension or on the contractile effect of carbachol, but inhibited vagally induced contractions in a concentration-dependent manner with a greater inhibition at low frequencies than at high. We suggest that the effect is exerted prejunctionally.
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| 6. |
- Lötvall, Jan, 1956, et al.
(author)
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The effect of formoterol over 24 h in patients with asthma: the role of enantiomers
- 2005
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In: Pulmonary Pharmacology & Therapeutics. - : Elsevier BV. - 1522-9629 .- 1094-5539. ; 18:2, s. 109-13
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Journal article (peer-reviewed)abstract
- The single-dose effect of formoterol racemate and enantiomers on bronchodilatation up to 24 h was determined. Forty-six reversible asthmatic patients were randomised to this double blind, crossover study. Formoterol was inhaled by nebulizer (HaloLite(R)); 4.5 and 36 mug of the racemate (rac-formoterol), 2.25 and 18 mug of (R;R)-formoterol, 18 mug of (S;S)-formoterol, or placebo. Airway and systemic effects were assessed by serial measurements of forced expiratory volume during the first second, FEV1 (24 h), and heart rate (4 h). Rac- and (R;R)formoterol significantly and dose-dependently increased FEV1, with similar mean maximal effect. (S;S)-formoterol was without significant effects on FEV1 and heart rate. (R;R)- and rac-formoterol were still effective 22-24 h after single high doses, but this was associated with some systemic side effect (increased heart rate) initially. Average 22-24 h FEV1 was 8% (rac-formoterol 36 mug) and 11% ((R-R)-formoterol 18 mug) over placebo, respectively. No significant differences in effects were observed between rac- and (R;R)-formoterol. Thus, the single dose bronchodilatating effect of formoterol resides in (R;R)-formoterol. This study does not indicate a clinically important advantage of (R;R)-formoterol as acute bronchodilator compared to the racemate.
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| 7. |
- Sang, Yutao, et al.
(author)
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Temperature Dependence of Charge and Spin Transfer in Azurin
- 2021
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In: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 125:18, s. 9875-9883
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Journal article (peer-reviewed)abstract
- The steady-state charge and spin transfer yields were measured for three different Ru-modified azurin derivatives in protein films on silver electrodes. While the charge-transfer yields exhibit weak temperature dependences, consistent with operation of a near activation-less mechanism, the spin selectivity of the electron transfer improves as temperature increases. This enhancement of spin selectivity with temperature is explained by a vibrationally induced spin exchange interaction between the Cu(II) and its chiral ligands. These results indicate that distinct mechanisms control charge and spin transfer within proteins. As with electron charge transfer, proteins deliver polarized electron spins with a yield that depends on the protein's structure. This finding suggests a new role for protein structure in biochemical redox processes.
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| 8. |
- Schmidt, D, et al.
(author)
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The effect of the vasoactive intestinal polypeptide agonist Ro 25-1553 on induced tone in isolated human airways and pulmonary artery
- 2001
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In: Naunyn-Schmiedeberg's Archives of Pharmacology. - : Springer Science and Business Media LLC. - 0028-1298 .- 1432-1912. ; 364:4, s. 314-320
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Journal article (peer-reviewed)abstract
- Ro 25-1553 is a metabolically stable analogue of endogenous vasoactive intestinal polypeptide (VIP). This compound is a potent bronchodilator in vitro as well as in vivo. Moreover, Ro 25-1553 has been shown to be highly selective of the VPAC2 receptor. We assessed the effect of Ro 25-1553 on isolated human bronchi and pulmonary arteries in vitro. Macroscopically normal human airways and pulmonary arteries were obtained from patients undergoing surgery for lung cancer. The relaxing capability of Ro 25-1553 on bronchial and pulmonary artery tone was measured using standard techniques. Bronchial rings were pre-contracted with 0.1 mM histamine, and tone in pulmonary artery rings was induced with 10 microM PGF2alpha. Increasing concentrations of Ro 25-1553 within a range of 1 pM to 10 microM were added and isometric tension changes were recorded. Ro 25-1553 caused a concentration-dependent relaxation of airway and pulmonary artery preparations, with an EC50 of approximately 10 nM and a maximal relaxation of 70%-75% of the induced tone. The presence of VPAC2 receptors in the two tissues, though low in density, was confirmed by in situ hybridization, immunocytochemistry and ligand binding. These findings indicate that the VIP analogue Ro 25-1553 may be useful in the treatment of asthma and/or chronic obstructive pulmonary diseases.
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| 9. |
- Waldeck, A. Reginald, et al.
(author)
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Electron paramagnetic resonance studies of succinate:ubiquinone oxidoreductase from Paracoccus denitrificans : Evidence for a magnetic interaction between the 3Fe-4S cluster and cytochrome b
- 1997
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In: Journal of Biological Chemistry. - : Elsevier BV. - 1083-351X .- 0021-9258.
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Journal article (peer-reviewed)abstract
- Electron paramagnetic resonance (EPR) studies of succinate:ubiquinone oxidoreductase (SQR) from Paracoccus denitrificans have been undertaken in the purified and membrane-bound states, Spectroscopic ''signatures'' accounting for the three iron-sulfur clusters (2Fe-2S, 3Fe-4S, and 4Fe-4S), cytochrome b, flavin, and protein-bound ubisemiquinone radicals have been obtained in air-oxidized, succinate-reduced, and dithionite-reduced preparations at 4-10 K. Spectra obtained at 170 K in the presence of excess succinate showed a signal typical of that of a flavin radical, but superimposed with another signal. The superimposed signal originated from two bound ubisemiquinones, as shown by spectral simulations, Power saturation measurements performed on the air-oxidized enzyme provided evidence for a weak magnetic dipolar interaction operating between the oxidized 3Fe-4S cluster and the oxidized cytochrome b. Power saturation experiments performed on the succinate- and dithionite-reduced forms of the enzyme demonstrated that the 4Fe-4S cluster is coupled weakly to both the 2Fe-2S and the 3Fe-4S clusters, Quantitative interpretation of these power saturation experiments has been achieved through redox calculations. They revealed that a spin-spin interaction between the reduced 3Fe-4S cluster and the cytochrome b (oxidized) may also exist. These findings form the first direct EPR evidence for a close proximity (less than or equal to 2 nm) of the high potential 3Fe-4S cluster, situated in the succinate dehydrogenase part of the enzyme, and the low potential, low spin b-heme in the membrane anchor of the enzyme.
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| 10. |
- Waldeck, K, et al.
(author)
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Actions of the new antimuscarinic compound Lu 25-109 on isolated human and pig detrusor.
- 2002
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In: Neurourology and Urodynamics. - : Wiley. - 0733-2467 .- 1520-6777. ; 21:1, s. 92-98
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Journal article (peer-reviewed)abstract
- The aim of this study was to evaluate the effects of a novel antimuscarinic agent, Lu 25-109, a partial M1 receptor agonist, and M2/M3 receptor antagonist in human and pig detrusor to establish its affinity for muscarinic receptors in human detrusor and parotid gland and to compare the results with those obtained with oxybutynin. Effects on the detrusor were determined as regards the ability to inhibit carbachol-induced contractions and contractions induced by electrical field stimulation (EFS). Radioligand binding studies were performed to assess the ability to displace quinuclidinyl benzilate (3H-QNB) from muscarinic receptors in the detrusor and parotid gland. Lu 25-109 produced a concentration-dependent rightward shift of the concentration-response curves for carbachol in both human and pig detrusor, the pK(b) values being 6.2+/-0.1 (n=6) and 5.8+/-0.3 (n=6). Corresponding values for oxybutynin were 7.9+/-0.1 (n=7) and 7.8+/-0.1 (n=6). Contractions induced by EFS in human detrusor were almost completely inhibited by 100 micromol/L Lu 25-109 (84+/-4%; n=4). In contrast, EFS-induced contractions in pig detrusor were less sensitive to Lu 25-109, resulting in a final inhibition of 32+/-6% (n=9) with the highest concentration used (100 micromol/L). This difference in effect between human and pig detrusor was not observed with oxybutynin. Radioligand binding experiments demonstrated a small difference in affinity for Lu 25-109 in the parotid gland compared with the bladder, the pKi values being 6.2+/-0.1 versus 6.5+/-0.1 (n=4). Corresponding values for oxybutynin were 8.5+/-0.1 versus 8.2+/-0.1 (n=4). The results show that Lu 25-109 competitively and effectively antagonizes carbachol-induced contractions and contractions induced by EFS in human detrusor muscle. Even if Lu 25-109 were less potent than oxybutynin, it has an effect profile that makes it of interest to test its ability to counteract bladder overactivity in humans.
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