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1.
Eeckhaut E Struijs K Possemiers S Vincken JP Keukeleire DD Verstraete W 《Journal of agricultural and food chemistry》2008,56(12):4806-4812
Estrogenic plant compounds from the human diet such as the lignan secoisolariciresinol diglucoside (SDG, 1) can exert biological activity in the human body upon ingestion and bioactivation to enterodiol (END, 5) and enterolactone (ENL, 6). Bioavailability of lignans is influenced by the food matrix and gut microbial action, of which the latter is subject to a large interindividual variation. In this study, the fate of the lignan precursor SDG, present in the lignan macromolecule of flax seed ( Linum usitatissimum), was determined during an artificial stomach and small intestinal digestion and during metabolism by two different enterolignan phenotypes in a TWINSHIME environment (TWIN Simulator of the Human Intestinal Microbial Ecosystem). The lignan macromolecule acted as a delivery system of SDG in the large intestine. SDG was only hydrolyzed into secoisolariciresinol (SECO, 2) through microbial action in the ascending colon, after which it was bioactivated into enterolignans from the transverse colon onward. Single demethylation was a first step in the bioactivation, followed by dehydroxylation. Enterolignan phenotypes remained stable throughout the experimental period. The establishment of END and ENL production equilibria reflected the subdominance of ENL-producing bacteria in the gastrointestinal tract. 相似文献
2.
Angelo Dewitte Tom Eeckhaut Johan Van Huylenbroeck Erik Van Bockstaele 《Euphytica》2010,171(2):283-293
In this study, treatments of both trifluralin (at 10, 100 and 1000 μM) and N2O (in the form of gas under pressure) were applied to Begonia flower buds to induce the formation of 2n pollen. Three male fertile species (B. cucullata, B. subvillosa var. leptotricha and B. fischeri) and two male sterile hybrids (B. schmidtiana × B. cucullata and B. subvillosa var. leptotricha × B. cucullata) were treated. Pollen size, which is related to pollen DNA content, increased after both N2O and trifluralin treatments, but the induction of large pollen was genotype dependent. Trifluralin induced large pollen only
in the male fertile species, while N2O treatments induced fertile 2n pollen in the male sterile B. schmidtiana × B. cucullata. Cytological studies showed that trifluralin induced multinuclear monads that resulted in 4n gametes in stead of 2n gametes.
In general, large pollen obtained after trifluralin treatments showed low germination capability, while large pollen obtained
after N2O treatments retained high germination capability. Seedlings with raised ploidy level could only be obtained after crosses
were performed with large pollen obtained from N2O treatments. Hence, N2O treatments are preferable to the use of trifluralin to induce 2n gametes in Begonia. 相似文献
3.
A. Osselaere L. De Bock V. Eeckhaut P. De Backer J. Van Bocxlaer K. Boussery S. Croubels 《Journal of veterinary pharmacology and therapeutics》2013,36(6):588-593
Cytochrome P450 is involved in drug metabolism. Subfamily CYP3A shows a degree of similarity across different animal species. However, little information is available about its expression and activity in broiler chickens. A RT‐PCR method was developed for the quantification of CYP3A37 expression in the liver and small intestine of broilers. A higher expression in the jejunum was observed compared with that in the ileum. In the liver, a significantly lower expression compared with that in the jejunum was noticed. Thus, the role of the small bowel in drug metabolism cannot be neglected in broilers. CYP3A activity was studied in vitro using midazolam as a substrate. Two protocols for the preparation of intestinal microsomes were compared. Mincing of the tissues before ultracentrifugation seemed to be more appropriate than a protocol based on ethylenediaminetetra‐acetic acid separation. CYP3A activity revealed to be the highest in the duodenum with a decreasing trend towards the ileum. Activity in liver was comparable to duodenal activity. 相似文献
4.
Reactivation of old landslides: lessons learned from a case-study in the Flemish Ardennes (Belgium) 总被引：1，自引：0，他引：1
M. Van Den Eeckhaut J. Poesen O. Dewitte A. Demoulin H. De Bo & M. C. Vanmaercke-Gottigny 《Soil Use and Management》2007,23(2):200-211
The number of human‐induced landslides is increasing worldwide, but information on the impact of human intervention on slope stability is often lacking. Therefore, this study analyses the Hekkebrugstraat landslide, the best‐recorded landslide in the Flemish Ardennes (Belgium). Information obtained from local inhabitants, aerial photographs and newspaper articles enabled a 50‐year reconstruction of both the landslide history and the land‐use changes at or close to the landslide site. The reconstruction suggests that anthropogenic preliminary factors such as: (i) the absence of well‐maintained drainage ditches in the affected area; (ii) the elevation of the surface of the road, i.e. a sunken lane, in the affected area; (iii) increased surface runoff from the drainage area; (iv) the creation of ponds; and (v) the removal of the lateral support at the landslide foot have played an important role in the reactivation of the Hekkebrugstraat landslide. After the reactivation of February 1995, landslide movement was observed for more than 5 years and caused damage to houses, and other infrastructure. However, also natural factors, such as the presence of an impermeable clay layer at limited depth, springs and relatively steep slopes (i.e. 0.14 m m?1), and above normal antecedent rainfall have contributed to the reactivations. Comparison of our reconstruction of the reactivation with precise Digital Terrain Models (DTMs) of 1952, 1973 and 1996, produced by digital stereophotogrammetry, indicated that the reported movements correspond well with the uplifted and collapsed zones found on the DTMs. Hence, this analysis provides valuable information for land‐use planners in areas with old, apparently stable, landslides. 相似文献
5.
Zhu C Feng S Sperandio V Yang Z Thate TE Kaper JB Boedeker EC 《Veterinary microbiology》2007,125(3-4):313-322
Attaching and effacing (A/E) organisms, such as rabbit enteropathogenic Escherichia coli (EPEC), human EPEC or enterohemorrhagic E. coli (EHEC) share attaching and effacing phenotype and LEE pathogenicity island responsible for A/E. The present study was undertaken to investigate the impact of the LuxS quorum sensing (QS) signaling system in vitro and in vivo pathogenicity of A/E organisms using rabbit EPEC (rEPEC) strain E22 (O103:H2). Analysis of the bioluminescence indicated abolished production of the QS signal AI-2 by luxS mutant (E22DeltaluxS). Strain E22Deltalux also exhibited impaired expression of several normally secreted proteins and reduced adherence to cultured HeLa cells. Complementation of the intact luxS gene to E22DeltaluxS restored secreted protein expression comparable to the WT type but not adherence to HeLa cells. In experimentally infected rabbits, the isogenic luxS mutant induced clinical illness and intimate adherence to the intestinal mucosa, albeit to a less extent, comparable to that seen with the parent virulent strain. It is worth noting that reduced fecal bacterial shedding, mucosal adherence and improved cumulative weight gain were seen for the mutant strain complemented with luxS when compared to the WT. It appears that the luxS gene is not essential for in vivo pathogenicity by rEPEC where exogenous QS signals are present in the gut. The impact of AI-2 provided by multicopy plasmid on bacterial virulence is discussed. 相似文献
6.
Emmy Dhooghe Sylvie Denis Tom Eeckhaut Dirk Reheul Marie-Christine Van Labeke 《Euphytica》2009,168(1):33-40
This study investigates the capacity of the antimitotic agents colchicine, oryzalin and trifluralin for inducing polyploidisation
of Ranunculus asiaticus ‘Alfa’ in vitro shoots. Flow cytometry was used to evaluate the optimal concentration of each antimitotic agent for polyploidisation.
Trifluralin at a concentration of 2 μM resulted in the highest percentage of polyploidisation (27.5%), followed by a colchicine
treatment of 200 μM, which induced 23.3% of polyploids. For oryzalin the highest percentage was achieved using a concentration
of 1 μM. Different exposure periods were tested and turned out to be an important factor. The maximal exposure period tested
(10 weeks) resulted in a significant increase in polyploidisation by oryzalin and trifluralin. In contrast, for colchicine
(100 μM) exposure times of either 16 or 24 h did not significantly influence polyploidisation. Additionally the effect of
the antimitotic agents on the viability was analysed. For colchicine no significant effect on the survival rate was observed,
for trifluralin only a concentration of 10 μM affected viability whereas for oryzalin, concentration as well as exposure period
were significant parameters. Flow cytometric data were confirmed by counting chromosomes in root tip cells. 相似文献
7.
J. Moeyersons M. Van Den Eeckhaut J. Nyssen Tesfamichael Gebreyohannes J. Van de Wauw J. Hofmeister J. Poesen J. Deckers Haile Mitiku 《CATENA》2008
Mass movement topography characterises the escarpments and piedmont zones of the tabular ridges in the western part of the Mekelle outlier, Tigray, Ethiopia. Several types of mass movements can be distinguished. The first type is rockfall produced by 357 km rocky escarpments and cliffs during the rainy season. In the study area, every current kilometer of Amba Aradam sandstone cliff annually produces 3.7 m3 of rock fragments. However, this is an under-estimation of the actual cliff and escarpment evolution, which is also characterised by debris slides and small rock slides. 相似文献
8.
Gholamiandehkordi Ahmadreza Eeckhaut Venessa Lanckriet Anouk Timbermont Leen Bjerrum Lotte Ducatelle Richard Haesebrouck Freddy Van Immerseel Filip 《Veterinary research communications》2009,33(8):1031-1037
The antimicrobial susceptibility of Clostridium perfringens strains isolated from Belgian broilers between May and September 2007 was investigated. All 39 tested isolates were sensitive
to enrofloxacin, erythromycin, tylosin, florfenicol and bacitracin. Twenty-six (66%) and 24 (61%) out of the 39 tested isolates
showed acquired resistance to tetracycline and lincomycin, respectively. The C. perfringens isolates were also screened by PCR for the presence of the resistance genes tet(K), tet(L), tet(M), tetB(P), tet(O), tet(W), lnu(A) and lnu(B). In 22/26 tetracycline resistant strains and 7/24 lincomycin resistant strains, resistance could be attributed to one
or more of these genes. An extended frequency distribution range of MICs was seen for ampicillin. These data are consistent
with data derived from studies carried out in 1980 and in 2004, indicating that no changes in antimicrobial resistance patterns
have taken place during time in C. perfringens isolates from broilers in Belgium. 相似文献
9.
Temperature related instability of a naturally induced cytoplasmic male sterility in industrial chicory (Cichorium intybus L.) 
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下载免费PDF全文 Jeroen Van der Veken Stany Vandermoere Olivier Maudoux Christine Notté Tom Eeckhaut Joost Baert Stefaan Werbrouck Johan Van Huylenbroeck 《Plant Breeding》2018,137(3):423-432
Natural alloplasmic cytoplasmic male sterile (CMS) clones of industrial chicory were obtained after crossing wild chicory with selected breeding lines. We investigated the CMS stability of 10 clones in various environmental growing conditions. CMS was stable under cool growing conditions in most of them. Fertility restoration, based on pollen production scores, was observed in all clones after a period of hot temperatures. The early flower bud stage was sensitive, resulting in fertile flowers 12–17 days after exposure to high temperatures. Experiments under controlled growing conditions at 15°C demonstrated that a heat shock of 2 days at 25 or 30°C was sufficient to restore fertility. Sterile flowers were formed when plants were again grown at lower temperatures. Significant differences between individual clones were observed, indicating the potential of genetic selection to obtain stable CMS parent lines. 相似文献
10.
Polyploidy is widespread in plants and has played a major role in the evolution and diversification of the plant kingdom.
Unreduced (2n) gametes are an interesting tool for polyploidisation and the creation of genetic variation in plant breeding.
Especially in ornamentals, polyploidisation can broaden attractive features within a species. A Begonia collection was screened on the occurrence of 2n pollen with the aid of four different techniques: pollen size measurement,
flow cytometric analysis of nuclei isolated from germinated and non germinated pollen, investigation of the microsporogenesis
and analysis of progeny. In ten of the 70 screened genotypes (B. dregei, B. pearcei, B. ‘Anna Christina’, B. ‘Bubbles’, B. ‘Florence Rita’, B. ‘Orococo’, B. ‘Rubaiyat’, B. ‘Spatflacier’, B. ‘Tamo’ and B276), large pollen were observed with a rather spherical than normal ellipsoidal shape. Flow cytometric data
proved that these aberrantly shaped pollen were associated with 2n ploidy levels, although they were not always viable. Meiotic
aberrations in these large pollen producers resulted mainly in dyads although also monads, triads and polyads were observed.
Successful crosses were obtained with B. dregei, B. ‘Orococo’, and B276 as pollinators; DNA content had increased in all or a part of the progeny. The results show that the
occurrence of 2n pollen is not a rare phenomenon in Begonia. 相似文献