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213.
Cervenka L Peskova I Foltynova E Pejchalova M Brozkova I Vytrasova J 《Current microbiology》2006,53(5):435-439
Seventeen spice and medicinal plant extracts (methanol and chloroform) were assayed for their antimicrobial activity against
Arcobacter butzleri, A. cryaerophilus, and A. skirrowii. In general, all of the tested extracts were able, to a different extent, to inhibit the growth of the selected Arcobacter species. Cinnamon, bearberry, chamomile, sage and rosemary extracts showed strong antimicrobial activity toward arcobacter
strains tested. Overall, the methanol extracts showed better activity than the chloroform extracts (P < 0.05); however, enhanced antibacterial activity of chloroform extracts of cinnamon and rosemary has been observed in comparison
with their methanol counterparts. The inhibitory dose of the most active extracts (the diameter of zone of inhibition ≥ 20
mm) was determined using the disc-diffusion method as well. 相似文献
214.
Harutiunian-Kozak BA Sharanbekian AB Kazarian AL Grigorian GG Kozak JA Sarkisyan GS Khachvankian DK 《Archives italiennes de biologie》2006,144(3-4):127-144
The spatial summation in receptive fields (RF) of single neurons in cat's extrastriate area 21a was investigated as a basic neurophysiological substrate for central integration processing of visual information. The results showed that the majority of investigated neurons changed their response patterns with gradual increase of applied stimulus size. In approximately 82% of cases the suppression of neuron discharges was observed when the length of the moving strip exceeded that of the RF. In some neurons the increased size of the moving stimulus leads to the changes in the RF substructure. Receptive fields of neurons recorded at the same microelectrode penetration depth showed a great variety of RF superpositions distributed in a spatially asymmetric manner. As a result, every single RF consists of multiple sub-regions within the RF, differing from each other by the number of superimposed RF-s (density factor). We suggest that such complex spatial organization of the RF provides the neurophysiological basis for central integration processing of the visual information. 相似文献
215.
Rego RO Kovár V Kopácek P Weise C Man P Sauman I Grubhoffer L 《Insect biochemistry and molecular biology》2006,36(4):291-299
A lectin, named Dorin M, previously isolated and characterized from the hemolymph plasma of the soft tick, Ornithodoros moubata, was cloned and sequenced. The immunofluorescence using confocal microscopy revealed that Dorin M is produced in the tick hemocytes. A tryptic cleavage of Dorin M was performed and the resulting peptide fragments were sequenced by Edman degradation and/or mass spectrometry. Two of three internal peptide sequences displayed a significant similarity to the family of fibrinogen-related molecules. Degenerate primers were designed and used for PCR with hemocyte cDNA as a template. The sequence of the whole Dorin M cDNA was completed by the method of RACE. The tissue-specific expression investigated by RT-PCR revealed that Dorin M, in addition to hemocytes, is significantly expressed in salivary glands. The derived amino-acid sequence clearly shows that Dorin M has a fibrinogen-like domain, and exhibited the most significant similarity with tachylectins 5A and 5B from a horseshoe crab, Tachypleus tridentatus. In addition, other protein and binding characteristics suggest that Dorin M is closely related to tachylectins-5. Since these lectins have been reported to function as non-self recognizing molecules, we believe that Dorin M may play a similar role in an innate immunity of the tick and, possibly, also in pathogen transmission by this vector. 相似文献
216.
Initiation of translation in prokaryotes and eukaryotes. 总被引:74,自引:0,他引:74
217.
Bailey D McKay Herman L MaysJr Yi-Wen Peng Kenneth H Kozak Cheng-Te Yao Hsiao-Wei Yuan 《BMC evolutionary biology》2010,10(1):71
Background
The subtropical island of Taiwan is an area of high endemism and a complex topographic environment. Phylogeographic studies indicate that vicariance caused by Taiwan's mountains has subdivided many taxa into genetic phylogroups. We used mitochondrial DNA sequences and nuclear microsatellites to test whether the evolutionary history of an endemic montane bird, Steere's Liocichla (Liocichla steerii), fit the general vicariant paradigm for a montane organism.Results
We found that while mountains appear to channel gene flow they are not a significant barrier for Steere's Liocichla. Recent demographic expansion was evident, and genetic diversity was relatively high across the island, suggesting expansion from multiple areas rather than a few isolated refugia. Ecological niche modeling corroborated the molecular results and suggested that populations of Steere's Liocichla are connected by climatically suitable habitat and that there was less suitable habitat during the Last Glacial Maximum.Conclusions
Genetic and ecological niche modeling data corroborate a single history--Steere's Liocichla was at lower density during the Last Glacial Maximum and has subsequently expanded in population density. We suggest that such a range-wide density expansion might be an overlooked cause for the genetic patterns of demographic expansion that are regularly reported. We find significant differences among some populations in F ST indices and an admixture analysis. Though both of these results are often used to suggest conservation action, we affirm that statistically significant results are not necessarily biologically meaningful and we urge caution when interpreting highly polymorphic data such as microsatellites.218.
Libor Dostál 《Inorganica chimica acta》2010,363(9):2051-2054
The synthesis and molecular structure of Me2LSn(1-Me-1,2-C2B10H10) (3), L is 2,6-(t-BuOCH2)2C6H3−, the precursor for the synthesis of other Sn ← O intramolecularly coordinated organotin(IV) compounds containing 1-methyl-o-carborane (1-Me-1,2-C2B10H11) is reported. Compound 3 was characterized by the help of 1H, 11B, 13C, 119Sn NMR spectroscopy and X-ray diffraction technique. For the preparation of 3, a novel triorganotin(IV) compound Me2LSnCl (2) has been prepared since the reaction of sterically more demanding Ph2LSnCl (1) with 1-Me-1,2-C2B10H10Li did not occur. 相似文献
219.
220.
Bradley Sanville Michael A. Dolan Kurt Wollenberg Yuhe Yan Carrie Martin Man Lung Yeung Klaus Strebel Alicia Buckler-White Christine A. Kozak 《PLoS pathogens》2010,6(7)
Mouse APOBEC3 (mA3) is a cytidine deaminase with antiviral activity. mA3 is linked to the Rfv3 virus resistance factor, a gene responsible for recovery from infection by Friend murine leukemia virus, and mA3 allelic variants differ in their ability to restrict mouse mammary tumor virus. We sequenced mA3 genes from 38 inbred strains and wild mouse species, and compared the mouse sequence and predicted structure with human APOBEC3G (hA3G). An inserted sequence was identified in the virus restrictive C57BL strain allele that disrupts a splice donor site. This insertion represents the long terminal repeat of the xenotropic mouse gammaretrovirus, and was acquired in Eurasian mice that harbor xenotropic retrovirus. This viral regulatory sequence does not alter splicing but is associated with elevated mA3 expression levels in spleens of laboratory and wild-derived mice. Analysis of Mus mA3 coding sequences produced evidence of positive selection and identified 10 codons with very high posterior probabilities of having evolved under positive selection. Six of these codons lie in two clusters in the N-terminal catalytically active cytidine deaminase domain (CDA), and 5 of those 6 codons are polymorphic in Rfv3 virus restrictive and nonrestrictive mice and align with hA3G CDA codons that are critical for deaminase activity. Homology models of mA3 indicate that the two selected codon clusters specify residues that are opposite each other along the predicted CDA active site groove, and that one cluster corresponds to an hAPOBEC substrate recognition loop. Substitutions at these clustered mA3 codons alter antiviral activity. This analysis suggests that mA3 has been under positive selection throughout Mus evolution, and identified an inserted retroviral regulatory sequence associated with enhanced expression in virus resistant mice and specific residues that modulate antiviral activity. 相似文献