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101.
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Lars Berglund Janne Brunstedt Klaus K. Nielsen Zhaochun Chen Jørn D. Mikkelsen Kjeld A. Marcker 《Plant molecular biology》1995,27(1):211-216
A gene (Chl) encoding a novel type of chitinase was isolated from Beta vulgaris. The Ch1 protein consists of an N-terminal hydrophobic prepeptide of 25 amino acids followed by a hevein-like domain of 22 amino acid residues, an unusually long proline-rich domain of 131 amino acid residues with 90 prolines, and finally a catalytic domain of 261 amino acid residues. Proteins with similar proline-rich domains are present in some other plants. The Chl gene shows a transient expression in response to fungal infection. 相似文献
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Probiotic effect of lactic acid bacteria in the feed on growth and survival of fry of Atlantic cod (Gadus morhua) 总被引:17,自引:0,他引:17
A growing concern for the high consumption of antibiotics in aquaculture has initiated a search for alternative methods of
disease control. Improved resistance against infectious diseases can be achieved by the use of probiotics. Probiotics are
live microorganisms supplemented in food or feed which give beneficial effects on the intestinal microbial balance. In the
present study a dry feed containing lactic acid bacteria (Carnobacterium divergens) isolated from Atlantic cod (Gadus morhua)intestines
was given to cod fry. After three weeks of feeding the fry was exposed to a virulent strain of Vibrio anguillarum. The death
rate was recorded during further three weeks of feeding with lactic acid bacteria supplemented feed. A certain improvement
of disease resistance was obtained, and at the end of the experiment lactic acid bacteria dominated the intestinal flora in
surviving fish given feed supplemented with lactic acid bacteria. No obvious growth inhibition of V. anguillarum was observed
in an in vitro mixed culture of this bacterium and the C. divergens isolated from cod intestines.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
107.
Coloboma Hyperactive Mutant Mice Exhibit Regional and Transmitter-Specific Deficits in Neurotransmission 总被引:3,自引:1,他引:2
Jacob Raber Prashant P. Mehta Max Kreifeldt Loren H. Parsons Friebert Weiss Floyd E. Bloom Michael C. Wilson 《Journal of neurochemistry》1997,68(1):176-186
Abstract: The mouse mutant coloboma ( Cm /+), which exhibits profound spontaneous hyperactivity and bears a deletion mutation on chromosome 2, including the gene encoding synaptosomal protein SNAP-25, has been proposed to model aspects of attention-deficit hyperactivity disorder. Increasing evidence suggests a crucial role for SNAP-25 in the release of both classical neurotransmitters and neuropeptides. In the present study, we compared the release of specific neurotransmitters in vitro from synaptosomes and slices of selected brain regions from Cm /+ mice with that of +/+ mice. The release of dopamine (DA) and serotonin (5-HT) from striatum, and of arginine vasopressin and corticotropin-releasing factor from hypothalamus and amygdala is calcium-dependent. Glutamate release from and content in cortical synaptosomes of Cm /+ mice are greatly reduced, which might contribute to the learning deficits in these mutants. In dorsal striatum of Cm /+ mutants, but not ventral striatum, KCI-induced release of DA is completely blocked and that of 5-HT is significantly attenuated, suggesting that striatal DA and 5-HT deficiencies may be involved in hyperactivity. Further, although acetylcholine failed to induce hypothalamic corticotropin-releasing factor release from Cm /+ slices, restraint stress increased plasma corticosterone levels in Cm /+ mice to a significantly higher level than in +/+ mice, suggesting an important role for arginine vasopressin in hypothalamic-pituitary-adrenal axis activation. These results suggest that reduced SNAP-25 expression may contribute to a region-specific and neurotransmitter-specific deficiency in neurotransmitter release. 相似文献
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C. N. Matthews R. Ludicky Jacob Schaefer E. O. Stejskal R. A. McKay 《Origins of life and evolution of the biosphere》1984,14(1-4):243-250
Cross-polarization magic-angle spinning15NMR spectra have been used to determine the composition of hydrogen cyanide polymers both before and after treatment with water. The unambiguous presence of secondary amide groups (as in peptide links) has been established by double-cross-polarization studies on the polymers synthesized from equimolar amounts of H13CN and HC15N. The NMR results are consistent with the hypothesis that the original heteropolypeptides on Earth were synthesized directly from hydrogen cyanide and water without the intervening formation of -amino acids. 相似文献