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41.
Pablo Arenaz 《Mutation research》1977,48(2):187-190
Seeds of varieties T219 and L65-1237 of Glycine max heterozygous for the Y11y11 gene combination (controlling chlorophyll development) were soaked for 0–24 h in aqueous solutions of hycanthone in concentration of 125 ppm to 1000 ppm and hycanthone plus FUdR in concentration of 5 × 10?7 to 2 × 10?6. Analysis of the simple leaves and the first compound leaf of the heterozygotes indicated that the drug did not increase the frequency of mutations or somatic crossing over in this system. 相似文献
42.
James W. Wallace Kenneth R. Markham David E. Giannasi John T. Mickel Don L. Yopp Luis D. Gomez J. Dan Pittillo Robert Soeder 《American journal of botany》1982,69(3):356-362
A survey for 1,3,6,7-tetrahydroxy-C-glycosylxanthones of representative species within the primitive vascular plants, emphasizing the leptosporangiate ferns, has indicated a limited distribution of these compounds within three leptosporangiate families: Hymenophyllaceae, Aspleniaceae and Marsileaceae. In the Hymenophyllaceae the distribution of these compounds appears to be a useful criterion for segregating species of Mecodium from other species of Hymenophyllum (sensu lato) and suggests that the tubulate vs. the valvate indusial condition may not be an ideal character for separating all species of Hymenophyllum (s.l.) from those of Trichomanes (s.l.). These compounds appear useful for delimiting several species of Elaphoglossum section Pachyglossa and support a relationship among the Aspleniaceae, Athyriaceae, and Elaphoglossaceae. Their presence in Marsilea also raises questions as to the origin of this group of plants. 相似文献
43.
Ricardo Pablo Garay 《生物化学与生物物理学报:生物膜》1982,688(3):786-792
Human erythrocytes are able to incorporate cyclic AMP (cAMP) in amounts larger than those required to saturate cAMP-dependent protein kinase. In contrast to previous observations in avian red blood cells in which cAMP stimulates the Na+/K+ cotransport system, we demonstrate that cAMP inhibits this system in human erythrocytes. The cotransport inhibition is enhanced by addition of phosphodiesterase inhibitor 1-methyl-3-isobutylxanthine to the incubation medium. The cAMP concentration giving half-maximal cotransport inhibition showed a wide variation among different individuals (from 0.1 to 5 mM external cAMP concentration). In contrast to cAMP, cyclic GMP showed little effect on the cotransport system. Ca2+ introduced into the cell interior was an inhibitor of the Na+/K+ cotransport system. These results suggest that in human cells in which endogeneous levels of cAMP and Ca2+ are modulated by hormones, the Na+/K+ cotransport system may be under hormonal regulation. 相似文献
44.
A. Jordá M. Gomez J. Cabo S. Grisolía 《Biochemical and biophysical research communications》1982,106(1):37-43
Streptozotocin induced diabetes in rats increased the activities of the three mitochondrial enzymes, carbamylphosphate synthetase, ornithine transcarbamylase and N-acetylglutamate synthetase, but not of the cytosolic N-acetylglutamate deacylase. Levels of both N-acetylglutamate and arginine, which are activators of carbamylphosphate synthetase and N-acetylglutamate synthetase respectively, increased in diabetes. These results serve to explain the increase both of mitochondrial citrulline and urea formation in hepatocytes and the increased urea excretion in diabetes. 相似文献
45.
46.
Pablo Collazo Lluís Montoliu Pere Puigdomènech Joan Rigau 《Plant molecular biology》1992,20(5):857-867
The isolation and characterization of cDNA and homologous genomic clones encoding the lignin O-methyltransferase (OMT) from maize is reported. The cDNA clone has been isolated by differential screening of maize root cDNA library. Southern analysis indicates that a single gene codes for this protein. The genomic sequence contains a single 916 bp intron. The deduced protein sequence from DNA shares significant homology with the recently reported lignin-bispecific caffeic acid/5-hydroxyferulic OMTs from alfalfa and aspen. It also shares homology with OMTs from bovine pineal glands and a purple non-sulfur photosynthetic bacterium. The mRNA of this gene is present at different levels in distinct organs of the plant with the highest accumulation detected in the elongation zone of roots. Bacterial extracts from clones containing the maize OMT cDNA show an activity in methylation of caffeic acid to ferulic acid comparable to that existing in the plant extracts. These results indicate that the described gene encodes the caffeic acid 3-O-methyltransferase (COMT) involved in the lignin biosynthesis of maize. 相似文献
47.
Lisbeth E. Gomez Pedro A.F. Lehmann 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1992,575(2)
A sensitive gas chromatographic method with flame ionization detection was developed for the analysis in plasma of the novel anticonvulsant d,l-3-hydroxy-3-ethyl-3-phenylpropionamide (HEPP), using d,l-2-hydroxy-2-ethyl-2-phenylacetamide as the internal standard. HEPP was extracted from alkalinized plasma into dichloromethane and quantified after derivatization with bis(trimethylsilyl)-trifluoroacetamide. Standard curves were linear from 0.5 to 50 and from 2 to 100 μg/ml of plasma, using 1.5 and 5 μg of the internal standard, respectively. The lower limit of detection at a signal-to-noise ratio of 3 standard deviations was 0.33 μg/ml of sample. The sensitivity, accuracy and reproducibility of the method were shown to be satisfactory for pharmacokinetic studies of HEPP. After intraperitoneal administration of 50 mg/kg to Wistar rats, the principal kinetic parameters were: absorption half-life = 0.04 h; volume of distribution = 1.32 l/kg; clearance = 4.40 ml/min; peak concentration = 50 μg/ml; peak time = 0.25 h; mean residence time = 4.55 h. 相似文献
48.
49.
Summary Boron, copper, iron, manganese and zinc concentrations were measured in sunflower leaves from plants grown hydroponically
in a closed continuous flow system and with boron concentrations ranging from deficient to toxic.
Leaves were analyzed at the stage of flower development. There was a highly significant inverse correlation between B concentration
in solution and Mn concentration in leaves.
Cu, Fe and Zn concentrations in the leaves were not changed by the different B levels, although the B concentration in leaves
increased with an increasing concentration in solution, showing a close correlation each other. 相似文献
50.