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31.
Michael J. Huether Paula J. Fedorka-Cray Mary Ann Pfannenstiel Gary A. Anderson 《FEMS microbiology letters》1987,48(1-2):179-182
Abstract This paper describes the plasmid profiles obtained for 73 of 96 field isolates of Haemophilus pleuropneumoniae serotypes 1, 3, 5, and 7. We also characterized the antibiotic susceptibilities of these 96 isolates. Because of the high proportion of isolates resistant to some of the antibiotics, no conclusions can be drawn as to the role of plasmids in antibiotic resistance. 相似文献
32.
Dr. Robert D. Prusch Stella-Maris Goette Paula Haberman 《Cell and tissue research》1989,255(3):553-557
Summary Phagocytosis in Amoeba proteus can be induced with prostaglandins (PG). In addition, arachidonic acid (the fatty acid precursor to the PG-2 series) also induces phagocytosis. The induction of phagocytosis with arachidonic acid can be partially inhibited by the cyclooxygenase inhibitor indomethacin. Phagocytosis in the amoeba can also be induced with the chemotactic peptide N-formylmethionyl-leucylphenylalanine (NFMLP). The peptide presumably induces phagocytosis by interacting with receptors on the amoeba surface, which may initiate the release of arachidonic acid from membrane lipids. NFMLP-induced phagocytosis can also be partially inhibited by indomethacin. It is suggested that PG's or biochemically related substances may play a signal-coupling role during phagocytosis in the amoeba. 相似文献
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Cristina Sánchez-Roldán Antonio Heredia Victoriano Valpuesta Martin J. Bukovac 《Journal of Plant Growth Regulation》1990,9(1-3):171-174
The indole-3-acetic acid (IAA) content in peach pericarp (Prunus persica L. Batsch cv. Merry) was highest at early stage I of development (200 ng/g fresh wt), decreased to the lowest level during stage II, and rose again at stage III to 60–70 ng/g fresh wt. High activity of glutamine synthetase was found in the pericarp during stage I. The soluble peroxidase activity was highest in the meso- and exocarp at stage II, and isoenzymatic changes in this fraction corresponded to the transition from cationic isoenzymes, predominant at stage I, to anionic isoenzymes at stage III. The ionically bound peroxidase activity in these tissues was highest at stage I. The three developmental stages showed marked differences in auxin content and enzyme activities; for peroxidases these changes reflect a developmental expression pattern for the isoenzymes. 相似文献
39.
Cristina Templado Joaquima Navarro Jordi Benet Anna Genescà M. Mar Pérez José Egozcue 《Human genetics》1988,79(1):24-28
Summary Sperm chromosome complements have been studied in a man heterozygous for a reciprocal translocation t(2;5)(p11;q15). Human sperm chromosomes were obtained after fertilization of zona-free hamster eggs. A total of 75 human sperm metaphases were analysed. Of the complements studied, 59 (78.6%) resulted from a 2:2 segregation and 16 (21.3%) from a 3:1 segregation, 4:0 segregation was not observed. Our results indicate that at least 36% of sperm complements were unbalanced with respect to the translocation. The frequency of other chromosome anomalies unrelated to the translocation was 16%. 相似文献
40.
Alessandro Negro Irene Martini Emilio Bigon Flavia Cazzola Cristina Minozzi Stephen D. Skaper Lanfranco Callegaro 《Gene》1992,110(2)
The gene(NGFB) encoding the β subunit of mature human nerve growth factor (hNGFB) was subcloned into the pJLA503 expression vector under the control of bacteriophage promoters pR and pL, and expressed in Escherichia coli. The recombinant protein represented approximately 3% of the total cellular protein. Biologically active hNGFB was solubilized (0.2% total NGFB) and purified by cation-exchange chromatography and it yielded two bands on polyacrylamide-gel electrophoresis under nonreducing conditions, corresponding to the monomeric (14 kDa) and homodimeric (26.5 kDa) forms of the molecule. Both hNGFB forms were immunopositive on Western blots with rabbit anti-NGFB antibodies; however, following additional purification, only the species corresponding to the hNGFB homodimer was biologically active on cultured chicken dorsal root ganglion neurons. These results demonstrate the feasibility of synthesizing the biologically active form of hNGFB in E. coli. 相似文献