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41.
42.
Jacob M?rup Schlütter Ida Kirkegaard Olav Bj?rn Petersen Nanna Larsen Britta Christensen David M. Hougaard Steen K?lvraa Niels Uldbjerg 《PloS one》2014,9(9)
Objective
To identify factors influencing the number of fetal cells in maternal blood.Methods
A total of 57 pregnant women at a gestational age of weeks 11–14 were included. The number of fetal cells in maternal blood was assessed in 30 ml of blood using specific markers for both enrichment and subsequent identification.Results
Participants carrying male fetuses had a higher median number of fetal cells in maternal blood than those carrying female fetuses (5 vs. 3, p = 0.04). Certain cytokines (RANTES, IL-2 and IL-5) were significantly associated with the number of fetal cells in maternal blood.Conclusion
The number of fetal cells in maternal blood is associated with certain cytokines and fetal gender. 相似文献43.
?ivind ?rstavik Ornella Manfra Kjetil Wessel Andressen Geir ?ystein Andersen Tor Skomedal Jan-Bj?rn Osnes Finn Olav Levy Kurt Allen Krobert 《PloS one》2015,10(3)
Aims
We recently published that the positive inotropic response (PIR) to levosimendan can be fully accounted for by phosphodiesterase (PDE) inhibition in both failing human heart and normal rat heart. To determine if the PIR of the active metabolite OR-1896, an important mediator of the long-term clinical effects of levosimendan, also results from PDE3 inhibition, we compared the effects of OR-1896, a representative Ca2+ sensitizer EMD57033 (EMD), levosimendan and other PDE inhibitors.Methods
Contractile force was measured in rat ventricular strips. PDE assay was conducted on rat ventricular homogenate. cAMP was measured using RII_epac FRET-based sensors.Results
OR-1896 evoked a maximum PIR of 33±10% above basal at 1 μM. This response was amplified in the presence of the PDE4 inhibitor rolipram (89±14%) and absent in the presence of the PDE3 inhibitors cilostamide (0.5±5.3%) or milrinone (3.2±4.4%). The PIR was accompanied by a lusitropic response, and both were reversed by muscarinic receptor stimulation with carbachol and absent in the presence of β-AR blockade with timolol. OR-1896 inhibited PDE activity and increased cAMP levels at concentrations giving PIRs. OR-1896 did not sensitize the concentration-response relationship to extracellular Ca2+. Levosimendan, OR-1896 and EMD all increased the sensitivity to β-AR stimulation. The combination of either EMD and levosimendan or EMD and OR-1896 further sensitized the response, indicating at least two different mechanisms responsible for the sensitization. Only EMD sensitized the α1-AR response.Conclusion
The observed PIR to OR-1896 in rat ventricular strips is mediated through PDE3 inhibition, enhancing cAMP-mediated effects. These results further reinforce our previous finding that Ca2+ sensitization does not play a significant role in the inotropic (and lusitropic) effect of levosimendan, nor of its main metabolite OR-1896. 相似文献44.
Øyvind Melien Laila S Nilssen Olav F Dajani Kristin Larsen Sand Jens-Gustav Iversen Dagny L Sandnes Thoralf Christoffersen 《BMC cell biology》2002,3(1):5-11
Background
Previous studies have shown that several agents that stimulate heptahelical G-protein coupled receptors activate the extracellular signal regulated kinases ERK1 (p44mapk) and ERK2 (p42mapk) in hepatocytes. The molecular pathways that convey their signals to ERK1/2 are only partially clarified. In the present study we have explored the role of Ca2+ and Ca2+-dependent steps leading to ERK1/2 activation induced by norepinephrine and prostaglandin (PG)F2α.Results
Pretreatment of the cells with the Ca2+ chelators BAPTA-AM or EGTA, as well as the Ca2+ influx inhibitor gadolinium, resulted in a partial decrease of the ERK response. Furthermore, the calmodulin antagonists W-7, trifluoperazine, and J-8 markedly decreased ERK activation. Pretreatment with KN-93, an inhibitor of the multifunctional Ca2+/calmodulin-dependent protein kinase, had no effect on ERK activation. The Src kinase inhibitors PP1 and PP2 partially diminished the ERK responses elicited by both norepinephrine and PGF2α.Conclusion
The present data indicate that Ca2+ is involved in ERK activation induced by hormones acting on G protein-coupled receptors in hepatocytes, and suggest that calmodulin and Src kinases might play a role in these signaling pathways. 相似文献45.
After a marked decline at the beginning of the 1900s, the arctic fox Alopex lagopus population in Fennoscandia has remained at a very low level. We suggest that the main cause for the population crash was
winter starvation caused by (1) over-hunting of reindeer Rangifer tarandus populations, and thus reduced carcass availability in the mountains, and (2) increased interspecific competition for these
carcasses because of increased invasion of red foxes Vulpes vulpes from lower altitudes. The failure of arctic fox populations to recover, despite increasing reindeer populations in the mid
1900s, can be explained by a concurrent strong increase in red fox numbers. Analyses of countywide hunting statistics from
Norway 1891–1920 suggest that there actually was an increase in red fox numbers in the period of arctic fox decline, and that
the increase in reindeer populations from the 1920s to the 1950s was accompanied by a new increase in red fox numbers. We
conclude that restoring arctic fox populations most likely will require a substantial and lasting reduction of red fox populations. 相似文献
46.
Kristin Tøndel Ulf G Indahl Arne B Gjuvsland Jon Olav Vik Peter Hunter Stig W Omholt Harald Martens 《BMC systems biology》2011,5(1):1-17
Background
Network inference methods reconstruct mathematical models of molecular or genetic networks directly from experimental data sets. We have previously reported a mathematical method which is exclusively data-driven, does not involve any heuristic decisions within the reconstruction process, and deliveres all possible alternative minimal networks in terms of simple place/transition Petri nets that are consistent with a given discrete time series data set.Results
We fundamentally extended the previously published algorithm to consider catalysis and inhibition of the reactions that occur in the underlying network. The results of the reconstruction algorithm are encoded in the form of an extended Petri net involving control arcs. This allows the consideration of processes involving mass flow and/or regulatory interactions. As a non-trivial test case, the phosphate regulatory network of enterobacteria was reconstructed using in silico-generated time-series data sets on wild-type and in silico mutants.Conclusions
The new exact algorithm reconstructs extended Petri nets from time series data sets by finding all alternative minimal networks that are consistent with the data. It suggested alternative molecular mechanisms for certain reactions in the network. The algorithm is useful to combine data from wild-type and mutant cells and may potentially integrate physiological, biochemical, pharmacological, and genetic data in the form of a single model. 相似文献47.
Richard Ward Christos Pliotas Emma Branigan Christian Hacker Akiko Rasmussen Gregor Hagelueken Ian R. Booth Samantha Miller John Lucocq James H. Naismith Olav Schiemann 《Biophysical journal》2014
Mechanosensitive channel proteins are important safety valves against osmotic shock in bacteria, and are involved in sensing touch and sound waves in higher organisms. The mechanosensitive channel of small conductance (MscS) has been extensively studied. Pulsed electron-electron double resonance (PELDOR or DEER) of detergent-solubilized protein confirms that as seen in the crystal structure, the outer ring of transmembrane helices do not pack against the pore-forming helices, creating an apparent void. The relevance of this void to the functional form of MscS in the bilayer is the subject of debate. Here, we report PELDOR measurements of MscS reconstituted into two lipid bilayer systems: nanodiscs and bicelles. The distance measurements from multiple mutants derived from the PELDOR data are consistent with the detergent-solution arrangement of the protein. We conclude, therefore, that the relative positioning of the transmembrane helices is preserved in mimics of the cell bilayer, and that the apparent voids are not an artifact of detergent solution but a property of the protein that will have to be accounted for in any molecular mechanism of gating. 相似文献
48.
Svend Olav Andersen 《Journal of insect physiology》1981,27(6):393-396
Cuticle from the metathoracic femur of adult locusts (Locusta migratoria) is characterized with respect to changes in water content and in protein extractability during maturation. The swelling behaviour and extractability of fully-sclerotized cuticle are compared to those of chemically-modified, unsclerotized cuticle.It is concluded that although dehydration may contribute to the stabilization of cuticle, it cannot account for the observed differences. The properties of mature cuticle can best be explained by the assumption that covalent cross-links are present between protein molecules. 相似文献
49.
Olav Aas 《Nordic Journal of Botany》1983,3(2):253-259
The following seven species of Coprotus from Norway are reported: C. disculus Kimbrough, Luck–Allen & Cain, C. granuliformis (Crouan) Kimbrough, C. lacteus (Cooke & Phillips) Kimbrough, Luck–Allen & Cain, of which Humana zamurensis Pat. & Gaill. is shown to be a taxonomic synonym, C. leucopocillum Kimbrough, Luck–Allen & Cain, C. luteus Kimbrough, Luck–Allen & Cain, C. ochraceus (Crouan) J. Moravec and C. sexdecimsporus (Crouan) Kimbrough & Korf. A key, comments on distribution and substrate preference are provided for the species treated. 相似文献
50.
Dr. Olav Giere 《Zoomorphology》1971,69(3):273-282
Coelo-rectal pygidial pores were found in the anal area of marine enchytraeids (Lumbricillus lineatus, Marionina spicula, Enchytraeus albidus) from the mud-flats of the Isle of Sylt. The structure and function of these pores have been discussed. 相似文献