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61.
62.
Tissue distribution and half-life of 125I-endothelin in the rat: importance of pulmonary clearance 总被引:3,自引:0,他引:3
M L Sirvi? K Mets?rinne O Saijonmaa F Fyhrquist 《Biochemical and biophysical research communications》1990,167(3):1191-1195
Plasma half-life and organ uptake of endothelin 1 (ET-1) was studied in anaesthetized Wistar rats administering a bolus of 125I-labeled ET-1 into jugular vein, with and without a preceding dose of 1-80 ng of unlabeled ET-1, via the same route. Plasma half-life of intact 125I-ET-1 was 40 sec and that of total radioactivity 68 sec. Immunoreactivity of circulating 125I-ET was rapidly reduced, by 23% at 30 sec and by 43% at 360 sec, respectively. High power liquid chromatography of plasma extracts revealed a corresponding decrease of intact 125I-ET-1 peak with time. There was a predominant uptake of 125I-ET-1 in the lungs, 82%, and lesser by kidneys, 10%, heart 3.6%, liver, 2.7%, and spleen, 1.5%, respectively. Pretreatment with unlabeled ET-1 caused a dose-dependent shift of uptake from lungs to kidneys. We conclude that circulating ET-1 is rapidly cleared, primarily by the lungs, which may play an important role in protecting the systemic circulation from the vasoconstricting actions of ET-1. 相似文献
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64.
C. E. Durel F. Laurens A. Fouillet Y. Lespinasse 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(8):1077-1085
Genetic parameters (narrow-sense heritabilities and genetic correlations) were estimated for major agronomical traits in
apple from large unbalanced data sets, with the help of wide-pedigree information. The software REML VCE (Groeneveld 1996)
took into account the complex pedigree of the French apple-breeding population, thanks to the restricted maximum likelihood
procedure combined with the construction of the entire relationship matrix between hybrids planted in the field and their
ancestors. Narrow-sense heritability estimates ranged from 0.34 to 0.68 for traits exhibiting a normal distribution. Heritability
values around 0.35–0.40 were obtained for fruit characteristics (size, texture, flavour, juice content, attractiveness, russeting).
Higher values of heritability were obtained for vigour, assessed by the circumference of the trunk (0.51), and powdery mildew
resistance (0.68). Additive genetic correlations between traits were also estimated, showing a very high relationship between
fruit-quality traits. Vigour and powdery mildew resistance were slightly correlated with the other traits. Utilization of
the ‘individual genetic model’ for the estimation of genetic parameters and breeding values in apple is discussed.
Received: 14 June 1997 / Accepted: 4 December 1997 相似文献
65.
Vallance BA Dijkstra G Qiu B van der Waaij LA van Goor H Jansen PL Mashimo H Collins SM 《American journal of physiology. Gastrointestinal and liver physiology》2004,287(4):G865-G874
The role of nitric oxide (NO) in inflammatory bowel diseases has traditionally focused on the inducible form of NO synthase (iNOS). However, the constitutive endothelial (eNOS) and neuronal (nNOS) isoforms may also impact on colitis, either by contributing to the inflammation or by regulating mucosal integrity in response to noxious stimuli. To date, studies examining the roles of the NOS isoforms in experimental colitis have been conflicting, and the mechanisms by which these enzymes exert their effects remain unclear. To investigate and clarify the roles of the NOS isoforms in gut inflammation, we induced trinitrobenzenesulfonic acid colitis in eNOS, nNOS, and iNOS knockout (KO) mice, assessing the course of colitis at early and late times. Both eNOS and iNOS KO mice developed a more severe colitis compared with wild-type mice. During colitis, iNOS expression dramatically increased on epithelial and lamina propria mononuclear cells, whereas eNOS expression remained localized to endothelial cells. Electron and fluorescence microscopy identified bacteria in the ulcerated colonic mucosa of eNOS KO mice, but not in wild-type, iNOS, or nNOS KO mice. Furthermore, eNOS KO mice had fewer colonic goblet cells, impaired mucin production, and exhibited increased susceptibility to an inflammatory stimulus that was subthreshold to other mice. This susceptibility was reversible, because the NO donor isosorbide dinitrate normalized goblet cell numbers and ameliorated subsequent colitis in eNOS KO mice. These results identify a protective role for both iNOS and eNOS during colitis, with eNOS deficiency resulting in impaired intestinal defense against lumenal bacteria and increased susceptibility to colitis. 相似文献
66.
Fitting of photon-count number histograms is a way of analysis of fluorescence intensity fluctuations, a successor to fluorescence correlation spectroscopy. First versions of the theory for calculating photon-count number distributions have assumed constant emission intensity by a molecule during a counting time interval. For a long time a question has remained unanswered: to what extent is this assumption violated in experiments? Here we present a theory of photon-count number distributions that takes account of intensity fluctuations during a counting time interval. Theoretical count-number distributions are calculated via a numerical solution of Master equations (ME), which is a set of differential equations describing diffusion, singlet-triplet transitions, and photon emission. Detector afterpulsing and dead-time corrections are also included. The ME-theory is tested by fitting a series of photon-count number histograms corresponding to different lengths of the counting time interval. Compared to the first version of fluorescence intensity multiple distribution analysis theory introduced in 2000, the fit quality is significantly improved. It is discussed how a theory of photon-count number distributions, which assumes constant emission intensity during a counting time interval, may also yield a good fit quality. We argue that the spatial brightness distribution used in calculations of the fit curve is not the true spatial brightness distribution. Instead, a number of dynamic processes, which cause fluorescence intensity fluctuations, are indirectly taken into account via the profile adjustment parameters. 相似文献
67.
The fluorescence decay kinetics of the photosystem I-only mutant strain of Chlamydomonas reinhardtii, A4d, are used to study energy transfer and structural organization in photosystem I (PSI). Time-resolved measurements over a wide temperature range (36-295 K) have been made both on cells containing approximately 65 core chl a/P700 and an additional 60-70 chl a + b from LHC proteins and on PSI particles containing 40-50 chl a/P700. In each case, the fluorescence decay kinetics is dominated by a short component, tau 1 which is largely attributed to the lifetime of the excitations in the core complex. The results are discussed in terms of simulations of the temperature dependence of tau 1 in model systems. Spectral inhomogeneity and the temperature dependence of the spectral lineshapes are included explicitly in the simulations. Various kinds of antenna arrangements are modeled with and without the inclusion of pigments with lower absorption energies than the trap (red pigments). We conclude that funnel arrangements are not consistent with our measurements. A random model that includes one or two red pigments placed close to the trap shows temperature and wavelength dependence similar to that observed experimentally. A comparison of the temperature dependence of tau 1 for cells and PSI particles is included. 相似文献
68.
Abou Bakari Kouassi Charles-Eric Durel Fabrizio Costa Stefano Tartarini Eric van de Weg Kate Evans Felicidad Fernandez-Fernandez Ceri Govan Anastasia Boudichevskaja Frank Dunemann Adriana Antofie Marc Lateur Marta Stankiewicz-Kosyl Andrzej Soska Kazimierz Tomala Markus Lewandowski Krzysztof Rutkovski Edwards Zurawicz Walter Guerra François Laurens 《Tree Genetics & Genomes》2009,5(4):659-672
Genetic parameters for apple (Malus x domestica) fruit external traits (fruit size, ground colour, proportion of over colour and attractiveness) and sensory traits (firmness, crispness, texture, juiciness, flavour, sugar, acidity and global taste) were estimated using 2,207 pedigreed genotypes from breeding programmes in six European countries. Data were scored for 3 years and four periods during storage. Analyses were performed with a restricted maximum likelihood method using VCE 5.1.2 software. Heritability estimates ranged from medium to high for instrumental traits. Genetic correlations between firmness and sugar were medium and low between firmness and acidity. Sensory traits showed low to high heritability, acidity and flavour being, respectively, the most and the less heritable. Global taste was strongly correlated with texture, juiciness, and flavour and relatively less correlated with crispness and acidity. Sensory sugar and acidity showed highly negative correlations whereas their instrumental measurements showed low and increasing positive correlations from harvest to 4 months post-harvest. Sugar exhibited a higher sensory/instrumental divergence. Conversely, instrumental and sensory firmness were highly correlated. Fruit external characteristics had medium heritability. Fruit attractiveness had highest and lowest correlations with fruit size and ground colour, respectively. Best linear unbiased predictors of breeding values were computed for all genotypes with the software PEST. The results were analysed with regard to the dynamic and the reliability of genetic parameters according to the scoring dates. Original issues of the study and the importance of the obtained results for efficient designs of further apple fruit quality breeding programmes were discussed. 相似文献
69.
70.
The effect of the plastoquionone (PQ) pool oxidation state on minimum chlorophyll fluorescence was studied in the green alga Chlamydomonas reinhardtii. In wild type and a mutant strain that lacks both photosystems but retains light harvesting complexes, oxygen depletion induced a rise in minimum chlorophyll fluorescence. An increase in minimum fluorescence yield is also observed when the PQ pool becomes reduced in the presence of oxygen and after application of an ionophore that collapses the transmembrane proton gradient. Together these results indicate that minimum chlorophyll fluorescence is modulated by the PQ oxidation state. 相似文献