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51.
Biological Trace Element Research - The analytical method used for the determination of traces of platinum and gold in different tissues of Wistar rats is based on neutron activation analysis with... 相似文献
52.
Carbon allocation in developing spruce needles. Enzymes and intermediates of sucrose metabolism 总被引:2,自引:0,他引:2
Rüdiger Hampp Bernd Egger Susanne Effenberger Werner Einig 《Physiologia plantarum》1994,90(2):299-306
In lyophilized needles of Norway spruce ( Picea abies [L.] Karsten) and starting from bud break, we determined enzyme activities (sucrose phosphate synthase [SPS; EC 2.4,1.14]. sucrose synthase [SS; EC 2.4,1.13]. acid invertase [AI; EC 3.2,1.26]) and intermediates (starch, sucrose, glucose, fructose; fructose 6-phosphate, fructose 2.6-bisphosphate [F26BP]) of carbohydrate metabolism together with needle weight, shoot length, chlorophyll and protein. For up to 110 days after bud break, samples were taken twice a week from about 25-year-old trees under field conditions. At least three periods can be distinguished during needle maturation. During the first period (up to 45 days after bud break) Al showed the highest extractable activity. This coincided with very high levels of F26BP (up to 11 pmol [mg dry weight]−1 ) and a transient increase of starch in parallel to a decrease of sucrose. The interval between 45 and 70 days after bud break was characterized by high SS activity (ratio of fructose/glucose >1), much decreased levels of F26BP (down to below 1 pmol [mg dry weight]−1 ), and a pronounced increase in the dry weight/fresh weight ratio. In parallel, starch declined and soluble carbohydrates increased. Finally, needle maturation was characterized by decreasing SS and continuously increasing SPS activities, so that the ratio of SPS/SS increased more than 6-fold. AI. however, did not decline with maturation. Changes in pool sizes of metabolites and enzyme activities (AI. SPS) are consistent with current concepts on sink/source transition. SS is obviously important with regard to the synthesis of structural polysaccharides. 相似文献
53.
Summary A cDNA clone encoding an ADP-ribosylation factor from potato (Solanum tuberosum L.) was isolated. The nucleotide and deduced amino acid sequences show high homology to known ADP-ribosylation factor sequences from Arabidopsis, yeast, cow and man. In northern blot experiments, all tissues analysed showed expression of the corresponding mRNA. Strongest expression was found, however, in potato tubers.Abbreviations ARF, ADP
ribosylation factor
- BSA
bovine serum albumin
- EDTA
ethylenediaminetetraacetic acid
- SDS
sodium dodecyl sulfate
- SSC
sodium saline citrate 相似文献
54.
S. L. K. Hsam F. J. Zeller 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,86(8):951-954
The present study describes the development of an alloplasmic haploid-inducer in durum wheat cv Cando. This cultivar possesses the homozygous wheat-rye translocation 1BL/1RS from the 6x-wheat cv Veery. The nucleus of 4x-Cando-Veery 1BL/1RS was introduced into Aegilops kotschyi cytoplasm by initially using (kotschyi)-Salmon as the maternal parent. In the cross of this alloplasmic durum line with Cando-Veery 1BL/1RS, which was used as the recurrent pollen parent, haploids (n=14) were produced. The frequency of haploids increased from 5.7% in the F1 generation to 14% in the BC1 generation. The presence of rye chromosome arm 1RS and the concomitant loss of 1BS in (kotschyi)-Cando-Veery 1BL/1RS are necessary for haploid induction. Proposals are made which may enable the use of haploids produced by nucleo-cytoplasmic interactions in future wheat breeding programs. 相似文献
55.
Bernd Nidetzky Marianne Hayn Ricardo Macarron Walter Steiner 《Biotechnology letters》1993,15(1):71-76
Summary The synergistic action of purified cellulases from Trichoderma reesei in hydrolysis of cellulose decreased with increasing substrate concentration, depended strongly on the the type of cellulose used, and was maximal on crystalline cellulose. Contrarily, the activity of the individual cellulases was highest on amorphous cellulose. The binary combinations CBH I/EG III and CBH I/CBH II exhibited the greatest degree of synergism on crystalline cellulose. 相似文献
56.
B. Proksch J. Blanz K. -P. Zeller G. Ehninger 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1994,658(2)
A high-performance liquid chromatographic method using ion-pairing chromatography on reversed-phase C18 material with a mobile phase of acetonitrile—water (19:81, v/v) containing 5 mM 1-pentanesulfonic acid was developed for the detection and separation of the anthrapyrazole CI-941 (I) and its metabolites. After sample clean-up with solid-phase extraction, I and its metabolites were measurable at a wavelength of 491 nm. A detection limit of 5 ng/ml was achievable for I. The dicarboxylic acid derivative and the isomers of the monocarboxylic acid derivative could be separated. Application of the method to a human pharmacokinetic study showed two and four metabolites of I in serum and urine respectively. 相似文献
57.
Bernd Johannsen Bernhard Noll Peter Leibnitz Günter Reck Steffi Noll Hartmut Spies 《Inorganica chimica acta》1993,210(2)
The reaction of mercaptoacetyl diglycine (MAG2) with technetium(V) gluconate in aqueous solution produced [TcO(MAG2)]−. A single X-ray structure determination was carried out for the tetraphenylarsonium salt. The dark brown crystals are monoclinic, space group P2(1)/n, with a=12.478(5), b=14.922(5), c=17.183(9) Å and Z=4. The [TcO(MAG2)]− ion has a square pyramidal geometry with the technetium atom displaced by 0.756 Å towards the oxo ligand from the plane formed by the equatorial S,N,N,O atoms. The rhenium complex AsPh4[ReO(MAG2)] was prepared analogously starting from Re(V) gluconate and characterized. 相似文献
58.
Bernd Engelmann 《Journal of cellular physiology》1993,157(2):403-407
The blood group antigen H (blood group O) and fucose-specific lectin Ulex europaeus agglutinin I (UEA1) (10 μg/ml) was found to increase the rate constant of CL? efflux into 100mM Na+ oxalate media by about 40% in erythrocytes taken from antigen H donors. In 100 mMK + oxalate, 150 mM Na+ pyruvate and in 150 mM Na+ acetate media the lectin elevated the rate constant of CL? efflux by 20–50%. The acceleration of Cl? efflux by UEA1 was completely blocked by 10 μM 4,4′-dllsothiocyanato-stilbene-2,2′-disulfonic acid (DIDS) indicating that the effect of the lectin is mediated by the anion exchanger of human erythrocytes (band 3 protein). In antigen A1 erythrocytes no significant stimulation of anion exchange by UEA1 was seen. The activation of Cl? efflux was completely prevented by addition of 1 mM fucose to the medium. These results suggest that the effect of UEA1 is mediated through interaction with the fucose residues of H antigens. Increasing extracellular Ca++ from 0.5 to 5 mM in Na + pyruvate or Na+ acetate media slightly reduced the acceleration of anion exchange by the lectin. On the other hand, replacing part of extracellular chloride by bicarbonate did not considerably alter the (previously reported) stimulatory effect of UEA1 on red blood cell Ca++ uptake. This suggests that the acceleration of anion exchange and of Ca++ uptake by UEA1, respectively, are mediated by different mechanisms. It is concluded that UEA1 activates anion exchange of human erythrocytes most probably by a direct interaction with H antigens present on extracellular domains of the band 3 protein. © 1993 Wiley-Liss, Inc. 相似文献
59.
Mehrdad Salamat Werner Götz Anette Horster Bernd Janotte Rainer Herken 《Cell and tissue research》1993,272(2):375-381
In the present investigation, we examined the role of trophoblast and parietal endoderm cells in the synthesis of carbohydrate-containing components of Reichert's membrane. To eliminate the function of Reichert's membrane as a filter between maternal and embryonal tissues we carried out our examination under in vitro conditions. Parietal yolk sac from mouse embryos on day 9 post coitum (p.c.) were cultivated for 0 to 5 days. Because tannic acid enables a complex formation between carbohydrates and osmium we chose the fixation with this acid for the ultrastructural study. Electron microscopy showed that for assembly of Reichert's membrane, trophoblast cells produce and then release components that were detected as tannic acid-positive granules both in the Reichert's membrane and in the vacuoles of the trophoblast cells. To localize specific carbohydrates we used postembedding-gold-lectin histochemistry on LR-GoldR-embedded tissues. Strong binding sites for the lectins WGA (Triticum vulgare), RCA I (Ricinus communis) and Con A (Canavalia ensiformis) were observed in Reichert's membrane and trophoblast cells but not in the parietal endoderm cells. The LTA (Lotus tetragonolobus)-binding pattern was positive in the membrane and its adjacent cells but that of the LFA (Limax flavus) was negative in the parietal endoderm cells and very weak in Reichert's membrane and trophoblast cells. Our results demonstrate that trophoblast cells are involved in the construction of Reichert's membrane through the production and release of specific glycoconjugates. 相似文献
60.
Markus M. Nöthen Thomas Eggermann Jeanette Erdmann Bernd Eiben Dieter Hofmann Peter Propping Gesa Schwanitz 《Human genetics》1993,92(4):347-349
The parental origin of the extra chromosome in trisomy 18 was traced in 30 informative families using highly polymorphic (CA) repeats mapped on the long arm of chromosome 18. Proband DNA was recovered from slides of chromosome preparations in 28 cases and from paraffin-embedded tissues in two cases. The extra chromosome was found to be of maternal origin in 26 cases (86.7%), and paternal origin in 4 cases (13.3%). 相似文献