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61.
A survey was conducted to determine the levels of fumonisins B1 and B2 in corn and corn-based products available in Colombia
for human and animal consumption. A total of 120 samples were analyzed by acetonitrile-water extraction, cleanup with a strong-anion-exchange
column, and liquid chromatography with o-phthaldialdehyde-2-mercaptoethanol derivatization and fluorescence detection. The
samples of corn and corn-based products for animal intake were taken at different feed manufacturing plants, whereas the samples
used for human foods where purchased from local retail stores. The number of positive samples for fumonisin B1 was 20.0% higher
in corn and corn-based products for animal intake (75.0%) than in corn and corn-based products for human consumption (55.0%).
The levels of fumonisin B1 were also higher in corn and corn-based products for animal intake (mean = 694 μg/kg; range = 32–2964
μg/kg), than in corn and corn-based products for human intake (mean = 218 μg/kg; range = 24–2170 μg/ kg). The incidence and
levels of fumonisin B2 were lower than those for fumonisin B1. Corn and corn-based products for animal consumption had an
incidence of fumonisin B2 of 58.3%, with a mean value of 283 μg/kg, and a range of 44–987 μg/kg. The incidence of fumonisin
B2 in corn-based products for human intake was 35.0%, with a mean value of 118 μg/kg and a range of 21–833 μg/kg. The highest
incidence and levels of fumonisins were found in samples of hominy feed, with concentrations ranging from 86 to 2964 μg/kg
fumonisin B1 and 57 to 987 μg/kg fumonisin B2. 相似文献
62.
K. Rudi M. Zimonja I.M. Aasen S.H. Knutsen S. Sahlstrøm 《Letters in applied microbiology》2009,48(4):433-439
Aims: The aim of this work was to analyse the growth of human faecal microbiota on barley dietary fibres (DF). It is generally accepted that insoluble DF are health promoting, but the information is scarce about how these fibres affect the gastrointestinal (GI) microbiota. A major reason for the limited knowledge is that there are currently no proper tools to analyse the complete GI microbiota.
Methods and Results: Here we present a novel 16S rRNA gene analytical approach that enables the analyses of the complete microbiota, including the part that has not yet been characterized. The basic principle of the method is use of 16S rRNA gene signature sequences to determine both the phylogenetic relatedness and the distribution of bacteria in the samples analysed.
Using this approach, we analysed the microbiota after in vitro fermentation of different barley fractions with human faeces. Our main finding was that groups of actinobacteria were selectively enriched by growth on the insoluble DF fractions.
Conclusions: Our novel analytical approaches revealed new enrichment patterns in the taxa that respond to insoluble DF.
Significance and Impact of the Study: Our results may have major implications for future understanding of insoluble DF health effects. 相似文献
Methods and Results: Here we present a novel 16S rRNA gene analytical approach that enables the analyses of the complete microbiota, including the part that has not yet been characterized. The basic principle of the method is use of 16S rRNA gene signature sequences to determine both the phylogenetic relatedness and the distribution of bacteria in the samples analysed.
Using this approach, we analysed the microbiota after in vitro fermentation of different barley fractions with human faeces. Our main finding was that groups of actinobacteria were selectively enriched by growth on the insoluble DF fractions.
Conclusions: Our novel analytical approaches revealed new enrichment patterns in the taxa that respond to insoluble DF.
Significance and Impact of the Study: Our results may have major implications for future understanding of insoluble DF health effects. 相似文献
63.
Mating experiments using Drosophila have contributed greatly to the understanding of sexual selection and behavior. Experiments often require simple, easy and cheap methods to distinguish between individuals in a trial. A standard technique for this is CO2 anaesthesia and then labelling or wing clipping each fly. However, this is invasive and has been shown to affect behavior. Other techniques have used coloration to identify flies. This article presents a simple and non-invasive method for labelling Drosophila that allows them to be individually identified within experiments, using food coloring. This method is used in trials where two males compete to mate with a female. Dyeing allowed quick and easy identification. There was, however, some difference in the strength of the coloration across the three species tested. Data is presented showing the dye has a lower impact on mating behavior than CO2 in Drosophila melanogaster. The impact of CO2 anaesthesia is shown to depend on the species of Drosophila, with D. pseudoobscura and D. subobscura showing no impact, whereas D. melanogaster males had reduced mating success. The dye method presented is applicable to a wide range of experimental designs. 相似文献
64.
65.
James Breen Thomas Wicker Xiuying Kong Juncheng Zhang Wujun Ma Etienne Paux Catherine Feuillet Rudi Appels Matthew Bellgard 《BMC plant biology》2010,10(1):98
Background
The complexity of the wheat genome has resulted from waves of retrotransposable element insertions. Gene deletions and disruptions generated by the fast replacement of repetitive elements in wheat have resulted in disruption of colinearity at a micro (sub-megabase) level among the cereals. In view of genomic changes that are possible within a given time span, conservation of genes between species tends to imply an important functional or regional constraint that does not permit a change in genomic structure. The ctg1034 contig completed in this paper was initially studied because it was assigned to the Sr2 resistance locus region, but detailed mapping studies subsequently assigned it to the long arm of 3B and revealed its unusual features. 相似文献66.
Rudi K Zimonja M Kvenshagen B Rugtveit J Midtvedt T Eggesbø M 《Applied and environmental microbiology》2007,73(8):2727-2734
We present a novel approach for comparing 16S rRNA gene clone libraries that is independent of both DNA sequence alignment and definition of bacterial phylogroups. These steps are the major bottlenecks in current microbial comparative analyses. We used direct comparisons of taxon density distributions in an absolute evolutionary coordinate space. The coordinate space was generated by using alignment-independent bilinear multivariate modeling. Statistical analyses for clone library comparisons were based on multivariate analysis of variance, partial least-squares regression, and permutations. Clone libraries from both adult and infant gastrointestinal tract microbial communities were used as biological models. We reanalyzed a library consisting of 11,831 clones covering complete colons from three healthy adults in addition to a smaller 390-clone library from infant feces. We show that it is possible to extract detailed information about microbial community structures using our alignment-independent method. Our density distribution analysis is also very efficient with respect to computer operation time, meeting the future requirements of large-scale screenings to understand the diversity and dynamics of microbial communities. 相似文献
67.
Noels H van Loo G Hagens S Broeckx V Beyaert R Marynen P Baens M 《The Journal of biological chemistry》2007,282(14):10180-10189
The recurrent translocation t(11;18)(q21;q21) associated with mucosa-associated lymphoid tissue (MALT) lymphoma results in the expression of an API2.MALT1 fusion protein that constitutively activates NF-kappaB. The first baculovirus IAP repeat (BIR) domain of API2 and the C terminus of MALT1, which contains its caspase-like domain, are present in all reported fusion variants and interact with TRAF2 and TRAF6, respectively, suggesting their contribution to NF-kappaB signaling by API2.MALT1. Also, the involvement of BCL10 has been suggested via binding to BIR1 of API2 and via its interaction with the immunoglobulin domains of MALT1, present in half of the fusion variants. However, conflicting reports exist concerning their roles in API2.MALT1-induced NF-kappaB signaling. In this report, streptavidin pulldowns of biotinylated API2.MALT1 fusion variants showed that none of the fusion variants interacted with endogenous BCL10; its role in NF-kappaB signaling by API2.MALT1 was further questioned by RNA interference experiments. In contrast, TRAF6 was essential for NF-kappaB activation by all fusion variants, and we identified a novel TRAF6 binding site in the second immunoglobulin domain of MALT1, which enhanced NF-kappaB activation when present in the fusion protein. Furthermore, inclusion of both immunoglobulin domains in API2.MALT1 further enhanced NF-kappaB signaling via intramolecular TRAF6 activation. Finally, binding of TRAF2 to BIR1 contributed to NF-kappaB activation by API2.MALT1, although additional mechanisms involving BIR1-mediated raft association are also important. Taken together, these data reveal distinct mechanisms of NF-kappaB activation by the different API2.MALT1 fusion variants with an essential role for TRAF6. 相似文献
68.
Janvilisri T Likitponrak W Chunchob S Grams R Vichasri-Grams S 《Molecular and cellular biochemistry》2007,305(1-2):95-102
Fatty acid binding proteins (FABPs) are capable of binding hydrophobic ligands with high affinity; thereby facilitating the
cellular uptake and intracellular trafficking of fatty acids. In this study, functional characteristics of a cytoplasmic FABP
from the giant liver fluke Fasciola gigantica (FgFABP) were determined. Binding of a fluorescent fatty acid analogue 11-[[5-dimethy aminonaphtalene-1-sulphonyl] amino]
undecanoic acid (DAUDA) to FgFABP resulted in changes in the emission spectrum. The optimal excitation wavelength and maximum
emission of fluorescence for binding activities with DAUDA were 350 nm and 550 nm, respectively. The binding activity for
DAUDA was determined from titration experiments and revealed a Kd value of 2.95 ± 0.54 μM. Furthermore, we found that cross-linking profile of FgFABP with dithiobis-(succinimidylpropionate)
(DSP) in the presence of DAUDA resulted in increased formation of higher-ordered oligomers compared to that in the absence
of DAUDA. We also replaced five highly conserved positively charged residues (K9, K58, K91, R107 and K131) with alanine and
studied their oligomerization and binding properties of the modified FgFABPs. The obtained data demonstrate that these residues
do not appear to be involved in oligomerization. However, the K58A and R107A substitutions exhibited a reduction in binding
affinities. K91A and R107A revealed an increase in maximal specific binding. 相似文献
69.
Christiane Trierweiler Ben J. Koks Rudi H. Drent Klaus-Michael Exo Jan Komdeur Cor Dijkstra Franz Bairlein 《Journal of Ornithology》2007,148(4):513-516
Autumn migration routes of two Dutch female Montagu’s Harriers (Circus pygargus) were documented for the first time using satellite telemetry. Both migrated to their African wintering area—one via the
Straits of Gibraltar through the Mediterranean and the other via Italy/Tunisia. The rate of travel was comparable to values
reported for larger raptor species. 相似文献
70.
The biomineralization of otoliths results mainly from the release of soluble Ca(2+), which is in turn precipitated as CaCO(3) crystals. In some Carapidae, sagittae sections have been shown to reveal a three-dimensional asymmetry with a nucleus close to the sulcal side, an unusual position. This study seeks to understand otolith formation in Carapus boraborensis. The unusual shape of the otolith is partly explained by the distribution of the epithelium cells, and particularly the sensory epithelium. Experimental evidence shows for the first time that aragonite growth takes place along the c-axis. These aragonite needles present two different habits. On the sulcal side is found the acicular form resulting from rapid growth during a short period of time. On the anti-sulcal side, the prismatic form seen there is due to a slower growth speed over longer periods. The otolith surface was observed each hour during a period of 24h in fishes reared in similar conditions. This allowed for the first time the direct observation on the otolith surface of the deposition of the two layers (L-zone and D-zone). In C. boraborensis, the organic-rich layer (D-zone) develops during the day, whereas the CaCO(3) layer (L-zone) seems to be deposited during the night. 相似文献