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1.
M. de Kwaadsteniet C. A. van Reenen L. M. T. Dicks 《Probiotics and antimicrobial proteins》2010,2(2):61-65
The potential of nisin F as an antimicrobial agent in treating subcutaneous skin infections was tested in vivo by infecting C57BL/6 mice with a bioluminescent strain of Staphylococcus aureus (Xen 36). Strain Xen 36 has the luxABCDE operon located on a native plasmid. Mice were grouped into four groups: Infected with strain Xen 36 and treated with nisin F, infected with strain Xen 36 and treated with saline (placebo), not infected and treated with nisin (control) and not infected and not treated (control). The immune systems of the mice were suppressed with deksamethasone. Mice were treated with either nisin F or sterile physiological saline 24 and 48 h after infection with subcutaneously injected S. aureus Xen 36 (4 × 106 CFU). Histology and bioluminescent flux measurements revealed no significant difference between infected mice treated with nisin and saline, respectively. However, infected mice treated with nisin F had an increased number of polymorphonuclear cells when compared with infected mice treated with saline. Also, not infected mice treated with nisin F had an influx of polymorphonuclear cells. Nisin F is thus ineffective in combating deep dermal staphylococcal infections. The apparent immune modulation of nisin when subcutaneously injected has to be investigated. 相似文献
2.
Erasmus Elardus Mason Shayne van Reenen Mari Steffens Francois E. Vorster B. Chris Reinecke Carolus J. 《Metabolomics : Official journal of the Metabolomic Society》2019,15(12):1-10
Metabolomics - Pre-eclampsia is a hypertensive gestational disorder that affects approximately 5% of all pregnancies. As the pathophysiological processes of pre-eclampsia are still uncertain, the... 相似文献
3.
Nyarukowa Christopher van Reenen Mari Koech Robert Mason Shayne Lindeque Zander Kamunya Samson Mose Richard Apostolides Zeno 《Journal of plant biochemistry and biotechnology.》2022,31(4):803-814
Journal of Plant Biochemistry and Biotechnology - Tea (Camellia sinensis) has enthralled both consumers and researchers, due to its taste, aroma and its medicinal attributes. Tea consumers concern... 相似文献
4.
Jacco C. van Rijssel Ellen S. Hoogwater Mary A. Kishe-Machumu Elize van Reenen Kevin V. Spits Ronald C. van der Stelt Jan H. Wanink Frans Witte 《Evolution; international journal of organic evolution》2015,69(1):179-189
Rapid morphological changes in response to fluctuating natural environments are a common phenomenon in species that undergo adaptive radiation. The dramatic ecological changes in Lake Victoria provide a unique opportunity to study environmental effects on cichlid morphology. This study shows how four haplochromine cichlids adapted their premaxilla to a changed diet over the past 30 years. Directly after the diet change toward larger and faster prey in the late 1980s, the premaxilla (upper jaw) changed in a way that is in agreement with a more food manipulating feeding style. During the 2000s, two zooplanktivorous species showed a reversal of morphological changes after returning to their original diet, whereas two other species showed no reversal of diet and morphology. These rapid changes indicate a potential for extremely fast adaptive responses to environmental fluctuations, which are likely inflicted by competition release and increase, and might have a bearing on the ability of haplochromines to cope with environmental changes. These responses could be due to rapid genetic change or phenotypic plasticity, for which there is ample evidence in cichlid fish structures associated with food capture and processing. These versatile adaptive responses are likely to have contributed to the fast adaptive radiation of haplochromines. 相似文献
5.
De Kwaadsteniet M Fraser T Van Reenen CA Dicks LM 《Applied and environmental microbiology》2006,72(7):4761-4766
Enterococcus faecium T8, isolated from vaginal secretions of children with human immunodeficiency virus, produces a class IIa sec-dependent bacteriocin that is structurally different from three other class IIa sec-dependent bacteriocins, i.e., enterocin P and an enterocin P-like bacteriocin, produced by Enterococcus faecium, and bacteriocin 31, produced by Enterococcus faecalis, and from a class III bacteriocin produced by E. faecalis. The genes encoding the bacteriocin, immunity protein, mobilization protein, and relaxase nuclease are located on a 7-kb plasmid. Bacteriocin T8 has a molecular mass of 5.1 kDa based on its DNA sequence, similar to the 5.0 kDa recorded for bacteriocin 31 but larger than the 4.6 kDa reported for enterocin P. At the amino acid level, bacteriocin T8 is 69% homologous to bacteriocin 31 and 47% homologous to enterocin P. Bacteriocin T8 is active against E. faecalis isolated from patients diagnosed with vaginosis, against Lactobacillus sakei, and against a Propionibacterium sp. The peptide is heat stable (60 min at 100 degrees C) and remains active in phosphate buffer from pH 4.0 to 10.0. The mode of activity is bactericidal, as determined with E. faecalis. 相似文献
6.
Johan J. Zonderland Maaike Wolthuis-Fillerup Cornelis G. van Reenen Marc B.M. Bracke Bas Kemp Leo A. den Hartog Hans A.M. Spoolder 《Applied animal behaviour science》2008,110(3-4):269-281
The aims of this study were to evaluate four preventive measures and two curative treatments of tail biting. The preventive measures were: chain, rubber hose, straw rack (5 g/pig/day) and the provision of straw on the floor twice daily by hand (2 × 10 g/pig/day). The two curative treatments, which were applied following the onset of tail biting in a pen were: straw twice daily (as in the fourth preventive measure) and the removal of the biter. In total, 960 undocked weaned piglets (10 piglets per pen) were observed during 5 weeks. Tail lesions (none, bite marks and wounds) were recorded daily. The incidence of pens with wounded pig tails was significantly lower when straw was provided twice daily (8% of pens) compared to the chain (58% of pens) and rubber hose (54% of pens) treatment, but did not differ significantly from the straw rack treatment (29% of pens). Tails with bite marks were significantly less common in pens with twice daily straw (16% of pens) compared to chain (88% of pens), rubber hose (79% of pens) and straw rack (75% of pens). No significant difference was found between the curative treatments. Both treatments showed a reduced incidence of red fresh blood on the tails at days 1–9 following curative treatment, compared to day 0. However, neither curative treatment eliminated tail biting entirely. In conclusion, this study indicates that tail biting is best prevented with a small amount of straw, provided twice daily, and to a lesser extent with a straw rack, compared to providing a chain or a rubber hose. Once tail biting has occurred, providing a small amount of straw twice daily and removing the biter appears to be equally effective. 相似文献
7.
A. van?Reenen F. Gutiérrez-Mejía L.J. van?IJzendoorn M.W.J. Prins 《Biophysical journal》2013,104(5):1073-1080
We report a method to profile the torsional spring properties of proteins as a function of the angle of rotation. The torque is applied by superparamagnetic particles and has been calibrated while taking account of the magnetization dynamics of the particles. We record and compare the torsional profiles of single Protein G-Immunoglobulin G (IgG) and IgG-IgG complexes, sandwiched between a substrate and a superparamagnetic particle, for torques in the range between 0.5 × 103 and 5 × 103 pN·nm. Both molecular systems show torsional stiffening for increasing rotation angle, but the elastic and inelastic torsion stiffnesses are remarkably different. We interpret the results in terms of the structural properties of the molecules. The torsion profiling technique opens new dimensions for research on biomolecular characterization and for research on bio-nanomechanical structure-function relationships. 相似文献
8.
Valerie van den Bos Otto Brinkkemper Ian D. Bull Stefan Engels Tom Hakbijl Mans Schepers Marieke van Dinter Guido van Reenen Bas van Geel 《Vegetation History and Archaeobotany》2014,23(3):277-298
Castellum Fectio was one of the largest fortifications along the Limes, the northern border of the Roman Empire. The castellum, situated 5 km southeast of Utrecht, the Netherlands, was occupied from around the start of our Era to ca. a.d. 260. It was situated along a river bend of the Rhine that was cut off from the main stream during the occupation of the Roman fort. A 6 m long sediment sequence was recovered from the infill of the residual channel and pieces of Roman wall plaster, glume bases of Triticum spelta and radiocarbon dates indicate that the sediments were deposited during the period of Roman occupation. The combined palaeoecological analyses—palynological, macrobotanical, entomological and geochemical—allow a detailed reconstruction of changing environmental conditions as a consequence of the Roman occupation. The pollen record reveals a dramatic decrease in arboreal pollen, suggesting that the Romans were involved in large-scale deforestation, transforming semi-open parkland to a landscape of meadows and agricultural fields. Non-pollen palynomorphs, botanical macrofossils and insect remains support this conclusion. The recorded mycoflora shows a shift from assemblages characterised by the tree pathogen Kretzschmaria deusta to assemblages dominated by spores of fungi associated with herbaceous plants, concurrent with the decrease in arboreal pollen. The presence of masticated bran fragments of cereals, clover remains, eggs of intestinal parasites and entomological and geochemical data in the upper part of the sequence indicates that these sediments largely consist of faeces that were dumped into the former channel. Surprisingly, seeds of salt tolerant species are encountered in the sediments of this inland site, which was situated outside the influence of the sea. Horses may have brought these seeds to Fectio in their intestinal tracts after grazing in coastal meadows. 相似文献
9.
Tooth size and the Carabelli trait 总被引:2,自引:0,他引:2
The Carabelli trait and its association with maxillary molar crown base and cusp size was studied in a group of 128 Kwengo, a San-Negro hybrid community living in Western Caprivi, Namibia. The trait was classified according to a modification of the scheme put forward by Dahlberg and by Scott (In: Dental Anthropology, New York: Pergamon, 1963) (Hum. Biol. 52:63-78, 1980). Crown base areas were larger in trait-positive than in trait-negative molars, and this difference existed for all eight categories of the trait in the first molar and for most of the categories in the second and third molars. The degree of expressivity of the trait seems to be associated with molar size, but this is more apparent in the first than in the second and third molars. 相似文献
10.
Gontse P. Moutloatse Madeleine J. Bunders Mari van Reenen Shayne Mason Taco W. Kuijpers Udo F. H. Engelke Ron A. Wevers Carools J. Reinecke 《Metabolomics : Official journal of the Metabolomic Society》2016,12(11):175