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1.
Contribution of methylated exudate flavonoids to the anti-inflammatory activity of Grindelia robusta
Liselotte Krenn Eckhard Wollenweber Katja Steyrleuthner Cornelia Görick Matthias F. Melzig 《Fitoterapia》2009
The flavonoid pattern of an acetonic extract of Grindelia robusta Nutt. was investigated in detail. The flavonoids were enriched by CC. In addition to twelve known methylated exudate flavonols four compounds were identified for the first time in G. robusta. Several substances of the flavonoid complex, among them the main compounds quercetin-3-methylether and 6-OH-kaempferol-3,6-dimethylether, were tested for their activity to inhibit neutrophil elastase. Quercetin-3-methylether was shown to be most active with an IC50 of 19 µM, thus obviously contributing to the anti-inflammatory activity of the drug. 相似文献
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Jouni Kilpeläinen Leena Finér Seppo Neuvonen Pekka Niemelä Timo Domisch Anita C. Risch Martin F. Jurgensen Mizue Ohashi Liselotte Sundström 《Forest Ecology and Management》2009
Ant–aphid mutualisms, in which ants tend aphids, which in turn provide honeydew to the ants, are widespread and have been shown to affect plant growth. In boreal forests the effect of ant–aphid mutualism on tree growth can vary with stand age, because forest clear-cutting harms the ecologically most dominant ant partner in such mutualisms, wood ants (Formica rufa group). We studied whether the mutualism between wood ants and Cinara aphids affects the growth of boreal Norway spruces (Picea abies L. Karst.) in stands of different ages. In boreal forests, conifers, unlike deciduous trees, have only few defoliating insects, and therefore we expected the growth loss of conifers due to sap sucking by aphids not to be compensated by reduced insect herbivory due to predation by wood ants. The study was conducted in medium-fertile spruce-dominated stands in eastern Finland. We used stands of four different age classes (5, 30, 60 and 100 years) and selected ten spruces heavily visited and ten spruces lightly visited by ants around five medium-sized ant mounds in each stand age class. The access of ants was blocked on half of the trees in both groups. In the 5-year-old stands, the mean annual height growth of individual heavily visited seedlings was 16.3% greater than in the ones where ant traffic was blocked, but this difference was not significant. In the 30-year-old stands, the mean annual radial growth of the heavily visited spruces was 7.3% smaller than in trees where ant traffic was blocked, and this difference was significant. The mutualism had no significant effect on the radial growth in the 60- and 100-year-old stands. In the 60-year-old stands, however, the spruces that were visited heavily prior to the beginning of the study grew significantly less relative to their past growth than the initially lightly visited trees during the study. This suggests that the ant–aphid mutualism may have long-term effects on tree growth. The ant–aphid mutualism had no significant effect on the growth at the stand level. The results indicate that ant–aphid mutualism can have a significant effect on the growth of individual spruces, but the effect is negligible at ecosystem level. 相似文献
3.
Analytical validation of a flow cytometric protocol for quantification of platelet microparticles in dogs 
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Sundström G Mowat JR Danared H Datz S Broström L Filevich A Källberg A Mannervik S Rensfelt KG Sigray P Ugglas MA Larsson M 《Science (New York, N.Y.)》1994,263(5148):785-787
Knowledge of the abundance of H(3)(+) is needed in interstellar and planetary atmospheric chemistry. An important destruction mechanism of H(3)(+) is low-energy electron impact followed by dissociation, but estimates of the reaction rate span several orders of magnitude. As an attempt to resolve this uncertainty, the cross section for dissociative recombination of vibrationally cold H(3)(+) has been measured with an ion storage ring down to collision energies below 1 millielectron volt. A rate coefficient of 1.15 x 10(-7) cubic centimeters per second at 300 kelvin was deduced. The cross section scaled with collision energy according to E(-1.15), giving thee rate a temperature dependence of T(-0.65). 相似文献
5.
Liselotte Rothmann Norup Tina S. Dalgaard Janne Pleidrup Anders Permin Torben W. Schou Gregers Jungersen Dorte R. Fink Helle R. Juul-Madsen 《Veterinary parasitology》2013,191(1-2):187-190
Increasingly large numbers of poultry are held in production systems with access to outdoor areas. In these systems intestinal helminths are found with flock prevalences of up to 100%. Helminth infections influence chicken health negatively, which is why the following investigation has been performed.In the present experiment, 20 chickens of two inbred chicken lines containing the major histocompatibility complex (MHC) haplotypes, B14 and R5, were inoculated with 500 embryonated Ascaridia galli eggs. The A. galli-specific IgG titres of serum samples and the excretion of A. galli eggs in chicken faeces were measured for a period of 81 weeks.The level of excreted A. galli eggs measured as eggs per gram chicken faeces (EPG) varied greatly between chickens in each line. Significant differences were found between the two lines and with the R5 chickens reaching the highest levels. Likewise, the A. galli-specific IgG titres in serum differed significantly between the two lines, and an inverse relationship between infection level (EPG) and antibody titres was found. Although this inverse relationship suggests that humoral immunity may be involved in protection against A. galli infection, the high antibody titres did not prevent continued infection. 相似文献
6.
Widén F Sundström E Gavier-Widén D Berg AL Dillner B Berg M 《Research in veterinary science》2012,92(3):509-511
A captive breeding programme for the Fennoscandian Arctic fox (Vulpes lagopus; syn. Alopex lagopus) failed due to fatal encephalitis. The aim of this study was to identify the causative agent. Viral nucleic acid was detected by PCR and in situ hybridization in the brain of affected foxes. The results suggest that a herpesvirus might be the causative agent. Whether this infection also occurs in free-living Arctic foxes is unknown. 相似文献
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T. Domisch M. Ohashi L. Finér A. C. Risch L. Sundström J. Kilpeläinen P. Niemelä 《Biology and Fertility of Soils》2008,44(3):539-545
Wood ants (Formica rufa group) are dominating ecosystem elements of the boreal region due to their wide and abundant occurrence. They collect and
concentrate organic material from the surrounding forest floor by building large above-ground mounds. These mounds have higher
temperature and lower water content than the surrounding forest floor. We studied how these peculiar environmental conditions
affected mass loss and carbon (C), nitrogen (N), phosphorus (P) and potassium (K) mineralisation of organic matter in boreal
Norway spruce (Picea abies L. Karst.)-dominated mixed forest stands of four different age classes (5-, 30-, 60-, and 100-year-old) situated in eastern
Finland using the litter bag technique. Norway spruce needle litter was incubated in inhabited and abandoned wood ant mounds
as well as on the surrounding forest floor. We expected decomposition to be extremely slow due to the dryness of the mounds.
Mass losses inside inhabited mounds were lower compared to the surrounding forest floor (on average 30 vs 50% after 2 years)
but not as low as we expected, which might be a result of ant and microbial activity in the mounds. Decomposition in the abandoned
mounds proceeded similarly as on the forest floor. Nutrient mineralisation proceeded more slowly in the ant mounds than on
the surrounding forest floor. Mineralisation occurred for all studied nutrients in the ant mounds, except for N, which net
amount remained stable during the years of the experiment. When wood ant mounds are abandoned and their porous and dry structure
is no longer maintained by the ants, their decomposition is accelerated, and nutrients may be available for uptake by plants,
although the nutrient mineralisation seems still to remain lower compared to the surrounding forest floor. However, eventually
the mound material will be decomposed and nutrients mineralised, thus providing a nutrient hot spot increasing the heterogeneity
of forest floor nutrient availability. 相似文献
9.
Jes Jessen Rasmussen Liselotte Wesley Andersen Trine Just Johnsen Jens Thaulow Marc Anglès d'Auriac Søren Nøhr Thomsen Martin Hesselsøe 《水产资源保护:海洋与淡水生态系统》2021,31(9):2506-2514
- Environmental DNA (eDNA) from water samples is increasingly used to detect the presence and distribution of species in aquatic ecosystems. However, before implementing eDNA in monitoring programmes, various species-specific sampling or analytical issues remain to be resolved in order to minimize frequencies of false-positive and -negative results. For example, empty shells from freshwater pearl mussels (Margaritifera margaritifera) contain extractable DNA (chemical extraction from ground-up shells) suggesting a risk of false-positive samples at stream sites with extinct populations but with empty shell material remaining.
- The aim of this study was to investigate whether empty and naturally degrading shells from M. margaritifera can cause false-positive eDNA signals in water samples.
- Water samples were collected from outdoor stream channels (in Lemming, Denmark) with living freshwater pearl mussels or empty shell material (density ~10 individuals m−2) during a 3-week experimental period. Living freshwater pearl mussels were collected from Hemgravs stream in Sweden and transported to Denmark according to permissions granted by the Swedish and Danish authorities.
- All water samples from stream channels containing empty shells were negative for eDNA indicating that eDNA traces in stream water are most likely to originate from living individuals located upstream of the sampling site. Water samples collected from stream channels containing living individuals of M. margaritifera were consistently positive for eDNA except for one sample (interpreted as a false negative).
- The study shows that positive eDNA signals for freshwater pearl mussels most likely reflect the presence of living individuals. Consequently, we suggest that eDNA should be used to locate remaining population fragments of M. margaritifera in deep and turbulent streams, providing a platform for faster and more efficient decision making when launching investigative and mitigation initiatives.
10.
Charlotta?AlmquistEmail author Lars?Persson ?sa?Olsson Jens?Sundstr?m Anders?Jonsson 《European journal of plant pathology / European Foundation for Plant Pathology》2016,145(4):731-742
Sugar beet root rot, caused by the oomycete Aphanomyces cochlioides, is a serious and economically important disease of sugar beets world-wide. Today, disease risk assessment consists of a time-consuming greenhouse bioassay using bait plants. In the present study, a real-time quantitative PCR (qPCR) assay for determination of A. cochlioides DNA in field-infested soil samples was developed and validated using the standard bioassay. The qPCR assay proved to be species-specific and was optimized to give high amplification efficiency suitable for target copy quantification. A high correlation (R2 > 0.98, p < 0.001) with pathogen inoculum density was shown, demonstrating the suitability for monitoring soil samples. The limit of detection (LOD) was evaluated in several different soil types and varied between 1 and 50 oospores/g soil, depending on clay content. Soils with a high LOD were characterised as having a low clay content and high content of sand. Varying levels of the A. cochlioides target sequence were detected in 20 of the 61 naturally infested soil samples. Discrepancies between the bioassay and the qPCR assay were found in soils from low- and medium-risk fields. However, the qPCR diagnostic assay provides a potentially valuable new tool in disease risk assessment, enabling sugar beet growers to identify high-risk fields. 相似文献