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21.
In comparison with the parental cv. Finale the ‘RisfixC’ supernodulator exhibited higher, continuously increasing nodule number and fresh mass accumulation, but substantially lower individual nodule fresh mass, leghemoglobin concentration, and specific acetylene reduction activity of nodule tissue. There were no substantial differences between Finale and ‘RisfixC’ in total acetylene reduction, nodule leghemoglobin accumulation per nodulated root, total and specific CO2 evolution from nodulated roots and gross CO2 respiratory costs of acetylene reduction. The ‘RisfixC’ also exhibited a substantially lower plant dry mass production (by 30%), but nitrogen concentration in shoots and carotenoid concentration in leaf tissue were significantly higher by 33 and 14%, and the chlorophylla+b content insignficantly higher than in the parental cultivar. In contrast, the nodulation mutant ‘Risnod29’, exhibited a somewhat higher nodule fresh mass accumulation (by 21%) and individual nodule fresh mass (by 23%), total and specific acetylene reduction (by 49 and 19%) and a somewhat more rapid plant dry mass accumulation compared with the cv. Finale. 相似文献
22.
Pawel Palkiewicz† Henk Zwiers† Fritz L. Lorscheider† 《Journal of neurochemistry》1994,62(5):2049-2052
Abstract: ADP-ribosylation is an essential process in the metabolism of brain neuronal proteins, including the regulation of assembly and disassembly of biological polymers. Here, we examine the effect of HgCl2 exposure on the ADP-ribosylation of tubulin and actin, both cytoskeletal proteins also found in neurons, and B-50/43-kDa growth-associated protein (B-50/GAP-43), a neuronal tissue-specific phosphoprotein. In rats we demonstrate, with both in vitro and in vivo experiments, that HgCl2 markedly inhibits the ADP-ribosylation of tubulin and actin. This is direct quantitative evidence that HgCl2, a toxic xenobiotic, alters specific neurochemical reactions involved in maintaining brain neuron structure. 相似文献
23.
Soldati Adrian Muhumuza Geresomu Dezecache Guillaume Fedurek Pawel Taylor Derry Call Josep Zuberbühler Klaus 《International journal of primatology》2023,44(1):116-139
International Journal of Primatology - Observations of early vocal behaviours in non-human primates (hereafter primates) are important for direct comparisons between human and primate vocal... 相似文献
24.
Yan, Sheng, Pawel Sliwinski, and Peter T. Macklem.Association of chest wall motion and tidal volume responses during CO2 rebreathing.J. Appl. Physiol. 81(4):1528-1534, 1996.The purpose of this study is to investigate theeffect of chest wall configuration at end expiration on tidal volume(VT) response duringCO2 rebreathing. In a group of 11 healthy male subjects, the changes in end-expiratory andend-inspiratory volume of the rib cage (Vrc,E andVrc,I, respectively) and abdomen (Vab,E and Vab,I, respectively) measured by linearizedmagnetometers were expressed as a function of end-tidalPCO2(PETCO2). The changes inend-expiratory and end-inspiratory volumes of the chest wall(Vcw,E and Vcw,I,respectively) were calculated as the sum of the respectiverib cage and abdominal volumes. The magnetometer coils were placed atthe level of the nipples and 1-2 cm above the umbilicus andcalibrated during quiet breathing against theVT measured from apneumotachograph. TheVrc,E/PETCO2 slope was quite variable among subjects. It was significantly positive (P < 0.05) in fivesubjects, significantly negative in four subjects(P < 0.05), and not different fromzero in the remaining two subjects. TheVab,E/PETCO2slope was significantly negative in all subjects(P < 0.05) with a much smallerintersubject variation, probably suggesting a relatively more uniformrecruitment of abdominal expiratory muscles and a variable recruitmentof rib cage muscles during CO2rebreathing in different subjects. As a group, the meanVrc,E/PETCO2,Vab,E/PETCO2, andVcw,E/PETCO2slopes were 0.010 ± 0.034, 0.030 ± 0.007, and0.020 ± 0.032 l / Torr, respectively;only theVab,E/PETCO2 slope was significantly different from zero. More interestingly, theindividualVT/PETCO2slope was negatively associated with theVrc,E/PETCO2(r = 0.68,P = 0.021) and Vcw,E/PETCO2slopes (r = 0.63,P = 0.037) but was not associated withtheVab,E/PETCO2slope (r = 0.40, P = 0.223). There was no correlation oftheVrc,E/PETCO2 andVcw,E/PETCO2slopes with age, body size, forced expiratory volume in 1 s, orexpiratory time. The groupVab,I/PETCO2 slope (0.004 ± 0.014 l / Torr) was not significantlydifferent from zero despite theVT nearly being tripled at theend of CO2 rebreathing. Inconclusion, the individual VTresponse to CO2, althoughindependent of Vab,E, is a function ofVrc,E to the extent that as theVrc,E/PETCO2slope increases (more positive) among subjects, theVT response toCO2 decreases. These results maybe explained on the basis of the respiratory muscle actions andinteractions on the rib cage. 相似文献
25.
Hilde De Boeck Frank G. Loontiens Halina Lis Nathan Sharon 《Archives of biochemistry and biophysics》1984,234(1):297-304
Erythrina cristagalli agglutinin, a dimeric lectin [J. L. Iglesias, et al. (1982) Eur. J. Biochem.123, 247–252] was shown by equilibrium dialysis to be bivalent for 4-methylumbelliferyl-β-d-galactoside. Upon binding to the lectin, this ligand showed a difference absorption spectrum with two maxima (at 322 and 336 nm) of equal intensity (Δ? = 1.2 × 103m?1 cm?1). A similar spectrum with a comparable value of Δ? was obtained with 4-methylumbelliferyl-N-acetyl-β-d-galactosaminide. Binding of methyl-α-d-galactoside, lactose, and N-acetyllactosamine all produced small but equally intense protein difference spectra with a maximum (Δ? = 2.8 × 102 M?1 cm?1) at 291.6 nm. Upon binding of N-dansyl-d-galactosamine to the lectin, there was a fivefold increase in fluorescence intensity of this ligand. The association constant for N-dansyl-d-galactosamine was caused by a very favorable ΔS° of the dansyl group without affecting the strictly carbohydrate-specific character of binding. N-Dansyl-d-galactosamine was employed as a fluorescent indicator ligand in substitution titrations. This involved the use of simple carbohydrates, N-acetyllactosamine, and oligosaccharides which occur in the carbohydrate units of N-glycoproteins; the latter were Gal(β → 4)GlcNAc(β1 → 2)Man, Gal(β1 → 4)GlcNAc(β1 → 6)Man, and Gal(β1 → 4)GlcNAc(β1 → 6)[Gal(β1 → 4)GlcNAc(β1 → 2)]Man. The titrations were performed at two temperatures to determine the thermodynamic parameters. In the series N-acetyl-d-galactosamine, methyl-α-d-galactoside, and lactose, ?ΔH° increased from 24 to 41 kJ mol?1; it increased further for N-acetyllactosamine and then remained unchanged for the N-acetyllactosamine-containing oligosaccharides (55 ± 1 kJ mol?1). This indicated that the site specifically accommodated the disaccharide structure with an important contribution of the 2-acetamido group in the penultimate sugar. Beyond this, no additional contacts seemed to be formed. This conclusion also followed from considerations of ΔS° values which became more unfavorable in the above series (?23 to ?101 ± 4 J mol?1 K?1); the most negative value of ΔS° was observed with N-acetyllactosamine and the three N-acetyllactosamine-containing oligosaccharides. 相似文献
26.
27.
When frog pars intermedia are incubated for 3 h with radioactive methionine, the predominant labeled peptide is one with an apparent molecular weight of 33, 100. This peptide can be immunoprecipitated with antisera against β-melanotropin (β-MSH), adrenocorticotrophin (ACTH), and β-endorphin and is believed to be the common precursor of ACTH and β-lipotropin (β-LPH). Immunoprecipitation experiments have also demonstrated the presence of labeled β-LPH and β-endorphin. The labeled β-endorphin has been shown to behave identically to sheep β-endorphin on both carboxymethyl-cellulose chromatography and polyacrylamide gel electrophoresis. Frog β-endorphin has methionine as the fifth residue, as do all other β-endorphins that have been sequenced. 相似文献
28.
Incubation of human T cells for 18 hr with prostaglandin E2 (PGE2 3 × 10?6M) causes a slight but significant increase in the percentage of Tγ cells and a reduction in Tμ cells. When PGE was added to “non-Tγ” cells, the increase in the percentage of Tγ cells was more marked (from 1.5% Tγ without PGE to 11% Tγ with PGE2, P < 0.001). Supernates from cultures of human monocytes also caused an increase in Tγ cells (10% Tγ without supernate to 18% with supernate, P < 0.01), and this increase was blocked if the monocytes were cultured with indomethacin, a prostaglandin synthetase inhibitor (9% Tγ cells). Thus, monocytes may regulate Fcγ receptors on T cells via PGE2 production. 相似文献
29.
No significant differences in the acetylene-reducing activity and evolution of H2 and CO2 nodulated roots ofPisum sativum inoculated with soilRhizobium populations from two soils with different acidities (Ruzyně soil 7.6; Lukavec soil 4.9) were observed.Rhizobium population from Lukavec soil formed nodules, exhibiting a higher H2 evolution. Co-inoculation with the Hup+ strain 128C30 (7×107 cells per seedling) eliminated, to some extent, the effect of soil populations on physiological activity.
Translated by Č. Novotny 相似文献
30.
Effect of inserted oxysterols on phospholipid packing in normal and sickle red blood cell membranes 总被引:1,自引:0,他引:1
R Szostek O Kucuk L J Lis D Tracy R Mata T Dey J W Kauffman S Yachnin M P Westerman 《Biochemical and biophysical research communications》1991,180(2):730-734
Fourier transform infrared (FTIR) spectroscopy was used to examine the effect of oxysterol insertion into normal and sickle RBC membranes and the total lipid extracts of the membranes. Examination of the FTIR C-H stretch and fingerprint regions reveal that the insertion of 7 alpha- and 7 beta-hydroxycholesterol has the greatest effect on the fluidity of RBC membranes and lipid extracts. The results confirm the observation that sterol molecules are oriented in the membrane so that the 7 position is located in the phospholipid head group region at the lipid/water interface. The substitution of a keto for a hydroxy group at the number seven position decreases the effect of the sterol on membrane packing. 相似文献