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691.
Changes in fetal and maternal blood levels of prolactin, cortisol, and cortisone during eutocic and dystocic childbirth 总被引:1,自引:0,他引:1
J R Van Cauwenberge J Hustin E Demey-Ponsart J Sulon A Reuter R Lambotte P Franchimont 《Hormone research》1987,25(3):125-131
The changes in blood levels of prolactin, total and free cortisol, and cortisone were studied and compared in 51 mother-infant pairs, 30 with eutocic delivery and 21 with dystocic delivery. Regardless of the type of delivery, the newborn at term showed significantly higher prolactin and cortisone serum levels than their mothers, and significantly lower levels of free and total cortisol. In fetal distress of short duration, free cortisol levels were significantly raised in both the mother and the child, while prolactin and cortisone levels were significantly higher only in the child. In contrast to these observations, serum prolactin and cortisone levels in the mother were not altered by the occurrence of fetal distress. In the newborn at delivery there was a negative correlation between serum prolactin and the Apgar score at 1 min applied to the part of the graph between 8 and 2 Apgar scores. This study illustrates the utility of fetal prolactin measurements in evaluating the stress to which the fetus is subjected. 相似文献
692.
Purification and molecular analysis of ribose-5-phosphate isomerase (EC5.3.1.6) from Saccharomyces cerevisiae is described first time. The enzymewas enriched from a haploid deletion mutant containing the wild-type gene ona multicopy plasmid elaborating the following steps: ammonium sulphateprecipitation, interfacial salting out on Sepharose 6B, high performanceliquid chromatography on Fractogel EMD DEAE and on Resource Phenyl. Theenzyme activity was found to be rather unstable possibly caused by removalof stabilizing cofactors or proteins during the purification procedure.The purified enzyme showed a hyperbolic dependence on the substrateribose-5-phosphate with a Km-value of 1.6±0.3 mmol/l.For the native enzyme a molecular mass of 115±10 kDa was determinedas found by saccharose density gradient centrifugation, sedimentationequilibrium analysis, size exclusion chromatography and polyacrylamide gelelectrophoresis. Sodium dodecyl sulphate polyacrylamide gel electrophoresisand Western blotting revealed one band with a molecular mass of 31±2kDa. Thus, the native enzyme is composed of four subunits of identicalsize.The molecular mass of the subunit and the identified N-terminal sequenceof 33 amino acids fits well the 258 amino acid protein encoded by the S.cerevisiae RKI open reading frame, which was characterized previously onlyby increasing specific activities of ribose-5-phosphate isomerase in cellsafter cloning the gene. On the basis of the conserved amino acids analignment of the amino acid sequence of ribose-5-phosphate isomerase fromyeast with those of the enzyme from mouse, spinach and Escherichia coli ispresented. 相似文献
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Peter F. Zipfel Michael Reuter 《International journal of peptide research and therapeutics》2009,15(2):87-95
All vertebrate species are constantly challenged by infectious agents and pathogens. In order to fight these infectious agents
the human host has developed a sophisticated and powerful immune defense. The complement system, which represents the first
defense line of innate immunity is activated immediately, within seconds. The activated immune system recognizes and damages
an invading microbe, coordinates the host immune response and further orchestrates the adaptive immune response. Activation
of the complement system leads to a rapid and amplified response which includes the generation of small peptides like C3a
and C4a that display antimicrobial, anti-fungal and anaphylactic activity. Here we report how these antimicrobial peptides
are generated during the immune response and summarize the functional mechanisms of these intrinsically generated anti microbial
peptides. 相似文献
698.
The enzymes of the GCN5-related N-acetyltransferase (GNAT) superfamily count more than 870 000 members through all kingdoms of life and share the same structural fold. GNAT enzymes transfer an acyl moiety from acyl coenzyme A to a wide range of substrates including aminoglycosides, serotonin, glucosamine-6-phosphate, protein N-termini and lysine residues of histones and other proteins. The GNAT subtype of protein N-terminal acetyltransferases (NATs) alone targets a majority of all eukaryotic proteins stressing the omnipresence of the GNAT enzymes. Despite the highly conserved GNAT fold, sequence similarity is quite low between members of this superfamily even when substrates are similar. Furthermore, this superfamily is phylogenetically not well characterized. Thus functional annotation based on sequence similarity is unreliable and strongly hampered for thousands of GNAT members that remain biochemically uncharacterized. Here we used sequence similarity networks to map the sequence space and propose a new classification for eukaryotic GNAT acetyltransferases. Using the new classification, we built a phylogenetic tree, representing the entire GNAT acetyltransferase superfamily. Our results show that protein NATs have evolved more than once on the GNAT acetylation scaffold. We use our classification to predict the function of uncharacterized sequences and verify by in vitro protein assays that two fungal genes encode NAT enzymes targeting specific protein N-terminal sequences, showing that even slight changes on the GNAT fold can lead to change in substrate specificity. In addition to providing a new map of the relationship between eukaryotic acetyltransferases the classification proposed constitutes a tool to improve functional annotation of GNAT acetyltransferases. 相似文献
699.
Four purified tRNALys species from 13-day-old chick embryo muscle have been characterized with respect to the following properties: qualitative oligoribonucleotide composition (polyacrylamide gel electrophoresis after RNase T1 digestion), anticodon response towards AAG and AAA (equilibrium dialysis and polylysine synthesis), strength of the aminoacyl bond (de-esterification kinetics), sedimentation coefficient, and temperature-dependent double helix-to-coil transition. The results confirm the existence of four molecularly independent lysine-specific tRNA's in this eukaryotic system. 相似文献
700.