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G. Stene-Larsen K. B. Helle 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1979,132(4):313-318
Summary The contractile force and frequency of the spontaneously beating auricles ofRana tempeoraria were recorded as a function of temperature. Tracings of the tension development, its integrated and derived functions showed that the isolated auricles of warmadapted winter frogs responded to temperature with changes in inotropy but not in the tension generated in one minute.Adrenaline, previously shown to act via the
in the auricles of this frog, increased both the force and the frequency of the contractions between 5 and 25°C. The affinity for adrenaline was highest at 5°C for all the parameters examined. The maximal effect (efficacy) of adrenaline for Tmax, Tmax and the tension-time integral was highest at 5°C while the efficacy of adrenaline on the heart rate reached its maximum at 25°C. At 5°C the tension generated in one minute was doubled by the maximally effective dose of adrenaline (1.4 × 10–6 M). These results strongly suggest that adrenaline, being the main sympathetic neurotransmitter in the frog, has an important role in adjusting the heart to maximal performance at the low temperatures. 相似文献
23.
Immunochemically identical hydrophilic and amphiphilic forms of the bovine adrenomedullary dopamine beta-hydroxylase. 总被引:2,自引:0,他引:2
By means of a monospecific antibody, dopamine beta-hydroxylase was monitored immunoelectrophoretically in various extracts of chromaffin granules. Approximately one-third of the dopamine beta-hydroxylase present was located in the membrane fraction and could only be liberated with detergent. The dopamine beta-hydroxylases of the buffer and membrane fractions were antigenically identical, but differed in their amphiphilicity, as demonstrated by the change in precipitation patterns on removal of Triton X-100 from the gel, on charge-shift crossed immunoelectrophoresis and on crossed hydrophobic interaction immunoelectrophoresis with phenyl-Sepharose. Furthermore, immunoelectrophoretic analysis in the presence of Triton X-100 plus the cationic detergent cetyltrimethylammonium bromide indicates additional heterogeneity of the membrane-bound dopamine-beta-hydroxylase. By limited proteolysis with chymotrypsin and thermolysin the amphiphilic form could be convered into its hydrophilic counterpart. 相似文献
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Nanna Brink Scholz Lars Bolund Mette Nyegaard Louise Faaborg Mette Warming J?rgensen Helle Lund Isa Niemann Lone Sunde 《PloS one》2015,10(11)
Hydatidiform moles (HMs) are abnormal human pregnancies with vesicular chorionic villi, imposing two clinical challenges; miscarriage and a risk of gestational trophoblastic neoplasia (GTN). The parental type of most HMs are either diandric diploid (PP) or diandric triploid (PPM). We consecutively collected 154 triploid or near-triploid samples from conceptuses with vesicular chorionic villi. We used analysis of DNA markers and/or methylation sensitive-MLPA and collected data from registries and patients records. We performed whole genome SNP analysis of one case of twinning (PP+PM).In all 154 triploids or near-triploids we found two different paternal contributions to the genome (P1P2M). The ratios between the sex chromosomal constitutions XXX, XXY, and XYY were 5.7: 6.9: 1.0. No cases of GTN were observed. Our results corroborate that all triploid human conceptuses with vesicular chorionic villi have the parental type P1P2M. The sex chromosomal ratios suggest approximately equal frequencies of meiosis I and meiosis II errors with selection against the XYY conceptuses or a combination of dispermy, non-disjunction in meiosis I and meiosis II and selection against XYY conceptuses. Although single cases of GTN after a triploid HM have been reported, the results of this study combined with data from previous prospective studies estimate the risk of GTN after a triploid mole to 0% (95% CI: 0–1,4%). 相似文献
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Agnieszka Wrobel Athanasios Saragliadis Jesús Pérez-Ortega Carolin Sittman Stephan Göttig Krystyna Liskiewicz Maria Helle Spence Kenneth Schneider Jack C. Leo Jesús Arenas Dirk Linke 《Environmental microbiology》2020,22(7):2939-2955
Yersinia ruckeri causes enteric redmouth disease (ERM) that mainly affects salmonid fishes and leads to significant economic losses in the aquaculture industry. An increasing number of outbreaks and the lack of effective vaccines against some serotypes necessitates novel measures to control ERM. Importantly, Y. ruckeri survives in the environment for long periods, presumably by forming biofilms. How the pathogen forms biofilms and which molecular factors are involved in this process, remains unclear. Yersinia ruckeri produces two surface-exposed adhesins, belonging to the inverse autotransporters (IATs), called Y. ruckeri invasin (YrInv) and Y. ruckeri invasin-like molecule (YrIlm). Here, we investigated whether YrInv and YrIlm play a role in biofilm formation and virulence. Functional assays revealed that YrInv and YrIlm promote biofilm formation on different abiotic substrates. Confocal microscopy revealed that they are involved in microcolony interaction and formation, respectively. The effect of both IATs on biofilm formation correlated with the presence of different biopolymers in the biofilm matrix, including extracellular DNA, RNA and proteins. Moreover, YrInv and YrIlm contributed to virulence in the Galleria mellonella infection model. Taken together, we propose that both IATs are possible targets for the development of novel diagnostic and preventative strategies to control ERM. 相似文献
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Montana Vedrana Flint Daniel Waagepetersen Helle S. Schousboe Arne Parpura Vladimir 《Neurochemical research》2021,46(10):2551-2579
Neurochemical Research - Astrocytes have a prominent role in metabolic homeostasis of the brain and can signal to adjacent neurons by releasing glutamate via a process of regulated exocytosis.... 相似文献
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Gabriella Galatà Andrés C. García-Montero Thomas Kristensen Ahmed A.Z. Dawoud Javier I. Muñoz-González Manja Meggendorfer Paola Guglielmelli Yvette Hoade Ivan Alvarez-Twose Christian Gieger Konstantin Strauch Luigi Ferrucci Toshiko Tanaka Stefania Bandinelli Theresia M. Schnurr Torsten Haferlach Sigurd Broesby-Olsen Hanne Vestergaard William J. Tapper 《American journal of human genetics》2021,108(2):284-294