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231.
Inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine the concentrations of 32 elements in the human liver and kidney and 20 elements in the bone, obtained from 70 autopsied dead individuals (54 males, 16 females) between 18 and 76 yr of age from the North Bohemia territory of the Czech Republic. Geometric means, median, minimal-maximal range, as well as distribution and correlation analysis were calculated. Some significant differences among tissue concentrations of trace elements of the women and men were found. In the liver, medians of the concentrations of some elements were higher for men than that for women (Al: 770 vs 610 microg/kg; As: 42 vs 27 microg/kg; Cd: 1800 vs 1390 microg/kg; Rb: 3955 vs 3210 microg/kg; V: 160 vs 105 microg/kg). On the contrary, the content of other elements for men was lower (Bi: 0.8 vs 3.2 microg/kg; Cr: 57 vs 72 microg/kg; Hg: 228 vs 325 microg/kg; Zn: 57.1 vs 68.5 mg/kg). In the kidney of men, there were higher contents of Al (360 vs 245 microg/kg) and Hg (135 vs 75 microg/kg) and lower contents of Zn (47.7 vs 59.7 mg/kg) and I (135 vs 220 microg/kg) than those of women. In the case of bone, the concentrations of Cu and Rb were higher for men (1410 microg Cu/kg and 405 microg Rb/kg, respectively) than for women (655 microg Cu/kg and 285 microg Rb/kg, respectively). On the contrary, the content of Mn was considerably lower for men (110 microg Mn/kg) than for women (215 microg Mn/kg). 相似文献
232.
L. Luhová M. Šebela I. Frébort L. Zajoncová H.G. Faulhammer P. Peč 《Biologia Plantarum》1998,41(2):241-254
Aim of this work was to find the best source for obtaining high amount of copper amine oxidase (EC 1.4.3.6) that can be further
used for analytical or industrial applications. The study focused on plant enzymes, because they occur in much higher content
in the starting material than the enzymes from other sources, have higher specific activity and are also more thermostable.
Presence of the amine oxidase was tested in extracts from 4 to 7-d-old seedlings of thirty-four various Fabaceae plants. Amine
oxidases from nine selected plants were purified by general method involving ammonium sulfate fractionation, controlled heat
denaturation, and three chromatographic steps. Kinetic properties of the amine oxidases purified were tested with a wide range
of substrates and inhibitors and were found to be very similar. Best purification yield, and total and specific activities
were obtained for the enzyme from grass pea (Lathyrus sativus) throughout all purification steps. Hence, the grass pea extract
was chosen as a suitable candidate for massive production of the amine oxidase.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
233.
234.
Václav Zídek Alena Musilová Jan Pintíř Miroslava Šimáková Michal Pravenec 《Mammalian genome》1998,9(7):503-505
Testicular weights were studied in the mouse BXD recombinant inbred (RI) strains. These strains were derived from DBA/2J
and C57BL/6J progenitors that differ significantly in their testicular weights (0.224 g ± 0.015 vs. 0.161 g ± 0.03, P < 0.0001).
The heritability of testicular weights was calculated to be 0.53, and the minimum number of responsible effective factors
was estimated to be 5.7. The total genome scanning of the BXD RI strains with over 1000 markers revealed a quantitative trait
locus (QTL) on mouse Chromosome (Chr) 13 near the D13Mit3 marker (LOD score 6.9). This QTL region was designated Twq1 and associated with over 75% of genetic variability.
Received: 23 January 1998 / Accepted: 16 March 1998 相似文献
235.
J. Štěpánek Jozef Kowalewski J. Lang Peter Mojzeš 《Journal of biological inorganic chemistry》1998,3(5):543-556
The interaction of Ni(II) ions with adenine mononucleotides (5′-AMP, 3′-AMP, 2′-AMP, 2′,3′-cAMP, 3′,5′-cAMP) was studied
in aqueous solution using Raman spectroscopy and 13C and 31P NMR paramagnetic relaxation measurements. Macrochelate structures were observed to form for all non-cyclic AMPs, with increasing
stability in the series: 3′-AMP < 2′-AMP < 5′-AMP. N7 of adenine was found to be the key site of the Ni(II)-adenine interaction
for all non-cyclic AMPs. For 2′-AMP, an alternative binding to the pyrimidine ring may also exist. The dependence of Raman
spectra on AMP and Ni(II) concentration confirmed the existence of a stable 1 : 2 Ni(II)-(5′-AMP) complex, besides the 1 : 1
complexes. In this complex, the adenine moieties of both 5′-AMP molecules are situated close to Ni(II), and their relative
orientations with respect to the cation are very similar. The paramagnetic relaxation enhancements of the carbons indicate
that the nickel ion is not located in the plane of the adenine units, but that the line connecting Ni(II) and N7 deviates
strongly from the adenine planes. Phosphates are outer-sphere coordinated by the cation. Findings from both methods have led
us to propose possible global architectures of the complex.
Received: 26 June 1998 / Accepted: 22 July 1998 相似文献
236.
Uroplakins and cytokeratins in the regenerating rat urothelium after sodium saccharin treatment 总被引:7,自引:2,他引:5
A sodium saccharin (NaSac) diet was used to induce cell damage and regeneration in the urothelium of the male rat urinary
bladder. Foci of terminally differentiated superficial cell exfoliation were detected after 5 weeks and their number increased
after 10 and 15 weeks of the diet. At the sites of superficial cell loss, regenerative simple hyperplasia developed. Within
5 weeks of NaSac removal, regeneration re-established normal differentiated urothelium. In order to follow urothelial differentiation
during regeneration we studied the expression of uroplakins and cytokeratins by means of immunocytochemistry and immunohistochemistry,
respectively. Normal urothelium was characterised by terminally differentiated superficial cells which expressed uroplakins
in their luminal plasma membrane and cytokeratin 20 (CK20) in the cytoplasm. Basal and intermediate cells were CK20 negative
and cytokeratin 17 (CK17) positive. In hyperplastic urothelium all cells synthesised CK17, but not CK20. Differentiation of
the superficial layer was reflected in three successive cell types: cells with microvilli, cells with rounded microridges
and those with a rigid-looking plasma membrane on the luminal surface. The cells with microvilli did not stain with anti-uroplakin
antibody. When the synthesis of uroplakins was detected rounded microridges were formed. With the elevated expression of uroplakins
the luminal plasma membrane becomes rigid-looking which is characteristic of asymmetric unit membrane of terminally differentiated
cells. During differentiation, syn-thesis of CK17 ceased in superficial cells while the synthesis of CK20 started. These results
indicate that during urothelial regeneration after NaSac treatment, specific superficial cell types develop in which the switch
to uroplakin synthesis and transition from CK17 to CK20 synthesis are crucial events for terminal differentiation.
Accepted: 19 August 1997 相似文献
237.
Christopher E. Anson Colin S. Creaser J.Allan Downie Orsolya Egyed Andrej V. Malkov Ljubica Mojovic G.Richard Stephenson Andrew T. Turner Karen E. Wilson 《Bioorganic & medicinal chemistry letters》1998,8(24):10883-3554
Derivatives of naringenin have been synthesized with organometalcarbonyl reporting groups for IR spectroscopy attached at C-2, C-3′, or C-6, and the products have been tested for the induction of nod gene expression using a Rhizobium leguminosarum strain which contains the Escherichia coli lacZ (β-galactosidase) gene fused to nodABC. Derivatives with an OMe substituent within the reporting group moiety showed residual gene induction activity. 相似文献
238.
239.
The effect of a dominant species, the litter layer, and the moss layer on seedlings and established vegetation was evaluated in two manipulative experiments in an oligotrophic wet meadow (Molinion with some features ofViolion caninae according to phytosociological classification). In the first experiment, the dominant species (Nardus stricta), litter layer, and litter layer together with the moss layer were removed and the response of the established vegetation and seedlings were compared with a control. Results revealed that after one season there was no significant effect of the treatments on established vegetation, but seedling recruitment was significantly affected. The greatest increase of seedling recruitment for many species was observed in the plots with the moss layer removed. In the second experiment, seeds ofSelinum carvifolia were sown into plots subjected to the following treatments: complete vegetation removal, mowing, mowing combined with removal of the moss layer, and an untreated control. The highest number of seedlings was found in plots with the vegetation removed, but the seedling recruitment was nearly as high in plots with the moss layer removed. Low numbers were found in mown plots and the lowest in the untreated control. The results show that seedling recruitment is more sensitive to competition than the established vegetation, at least over one season. This supports the idea of the importance of the regeneration niche for the maintenance of diversity in grassland communities. 相似文献
240.
Rebeka Fijan Michele Basile Sonja Šostar-Turk Ema Žagar Majda Žigon Romano Lapasin 《Carbohydrate polymers》2009,76(1):8-16
Polysaccharide thickeners (alginate, carboxymethylated guar gum and carboxymethylated cellulose) used for the preparation of printing pastes, were recycled from printing paste residues and from wastewater concentrates, which were separated by ultrafiltration technique from wastewater after screen printing of cotton with reactive dyes. Concentrated aqueous polysaccharide solutions were studied via rheological measurements under steady and oscillatory shear conditions. Molecular weight averages and molecular weight distribution of thickeners were determined by size exclusion chromatography.A satisfactory fitting of viscosity data is obtained with the Cross equation and mechanical spectra are described with satisfactory approximation with the Friedrich–Braun model. The obtained parameters enable a quantitative interpretation of the changes in rheological properties. Moderate changes produced by thickener recycling on the shear-thinning and viscoelastic behaviour of polymers are a direct result of changes in molecular weight averages (MWA) and molecular weight distribution (MWD). 相似文献