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101.
Christina Henneke Anna Jespersen Stine Jacobsen Martin K Nielsen Fintan McEvoy Henrik E Jensen 《Acta veterinaria Scandinavica》2014,56(1)
The majority of Halicephalobus gingivalis-infections in horses have been fatal and are usually not diagnosed before necropsy. Therefore, knowledge about the nematode and the pathogenesis of infection in horses is limited. This has resulted in an on-going discussion about the port of entry and subsequent dissemination of H. gingivalis within the host. The present case of H. gingivalis-infection in a horse was diagnosed ante mortem. Post mortem findings, the distribution pattern of H. gingivalis nematodes in the brain, a high prevalence of inflammation in close relation to blood vessels, and the presence of the nematode in multiple organs with a disseminated pattern of distribution strongly suggested a haematogenous spread of the nematode in the horse. 相似文献
102.
Anette B Grossi J?rgen S Agerholm Knud Christensen Henrik E Jensen Páll S Leifsson Christian Bendixen Peter Karlskov-Mortensen Merete Fredholm 《Acta veterinaria Scandinavica》2014,56(1)
Background
Peripheral nerve sheath tumors (PNSTs) are frequently found in Danish cattle at slaughter. Bovine PNSTs share several gross and histopathological characteristics with the PNSTs in humans with heritable neurofibromatosis syndromes. The aim of the present study was to investigate a possible hereditary disposition to PNSTs in dairy cattle by statistical analysis performed on data from 567 cattle with PNSTs. Furthermore, a preliminary genome-wide association study (GWAS) was performed on DNA isolated from 28 affected and 28 non-affected Holstein cows to identify loci in the bovine genome involved in the development of PNSTs.Results
PNSTs were significantly more common in the Danish Holstein breed than in other breeds with 0.49% of Danish Holsteins slaughtered during an eight-year-period having PNSTs. PNSTs also occurred significantly more frequently in the offspring of some specific Holstein sires. Examination of three generation pedigrees showed that these sires were genetically related through a widely used US Holstein sire. The PNSTs included in GWAS were histologically classified as neurofibroma-schwannoma (43%), schwannoma (36%) and neurofibroma (21%) and derived from Holstein cows with multiple PNSTs. A single SNP on chromosome 27 reached genome-wide significance.Conclusions
Gross and histological characteristics of bovine PNSTs are comparable to PNSTs in humans (schwannomatosis). Danish Holsteins are genetically disposed to develop PNSTs but the examined materials are insufficient to allow determination of the mode of inheritance. 相似文献103.
Late Pleistocene organic-rich sediments (sapropels) from the eastern Mediterranean Sea harbor unknown, metabolically active chemoorganotrophic prokaryotes. As compared to the carbon-lean intermediate layers, sapropels exhibit elevated cell numbers, increased activities of hydrolytic exoenzymes, and increased anaerobic glucose degradation rates, suggesting that microbial carbon substrates originate from sapropel layers up to 217,000 years old. 16S ribosomal RNA gene analyses revealed that as-yet-uncultured green nonsulfur bacteria constitute up to 70% of the total microbial biomass. Crenarchaeota constitute a smaller fraction (on average, 16%). A slow but significant turnover of glucose could be detected. Apparently, sapropels are still altered by the metabolic activity of green nonsulfur bacteria and crenarchaeota. 相似文献
104.
The actions of many extracellular stimuli are elicited by complexes of cell surface receptors, heterotrimeric guanine nucleotide-binding proteins (G proteins), and mitogen-activated protein (MAP) kinase complexes. Analysis of haploid yeast cells and their response to peptide mating pheromones has produced important advances in our understanding of G protein and MAP kinase signaling mechanisms. Many of the components, their interrelationships, and their regulators were first identified in yeast. Current analysis of the pheromone response pathway (see the Connections Maps at Science's Signal Transduction Knowledge Environment) will benefit from new and powerful genomic, proteomic, and computational approaches that will likely reveal additional general principles that are applicable to more complex organisms. 相似文献
105.
OPS法玻璃化冷冻牛卵母细胞和囊胚 总被引:13,自引:5,他引:13
本文报道了利用拉细开口型细管 (Open Pulled Straw,OPS)方法进行玻璃化冷冻保存体外成熟(IVM)的牛卵母细胞及体外生产 (IVP)的牛囊胚的实验结果。实验 1的牛卵母细胞冷冻处理分 2组 ,组 1(G1 )是将卵母细胞在 IVM2 1 h时去除部分卵丘细胞后马上进行冷冻处理。组 2 (G2 )卵母细胞在 IVM6h时去除部分卵丘细胞 ,然后继续培养至 2 2 h冷冻 ;冷冻后的卵母细胞在液氮中保存 0 .5~ 2 h后解冻再继续 IVM1 h后与正常 IVM2 4h的对照组卵母细胞一起进行体外受精 (IVF)处理。实验 2则冷冻了来自IVP的 6、 7日龄的牛囊胚。结果显示 ,G1的卵母细胞 IVF后 8d的囊胚率 (2 2 .8% ,2 6/1 1 4)和孵化囊胚率 (1 4.9% ,1 7/1 1 4)都极显著地高于 G2 (分别为 2 .9% ,5 /1 71和 0 .5 % ,1 /1 71 ,P<0 .0 0 1 ) ;但两处理组的受精卵裂率差别不大 (分别为 48.2 %和 41 .5 % ,P>0 .3 )。冷冻第 6d和第 7d的体外囊胚 ,其冻后存活率和囊胚孵化率分别为 92 .7%、 89.2 %和 83 .6%、 66.7%。结果表明 ,利用 OPS法玻璃化冷冻经体外培养成熟的牛卵母细胞及体外生产的牛囊胚均能获得良好的效果 相似文献
106.
Kati?VaajasaariEmail author Anneli?Joutti Eija?Schultz Salla?Selonen Henrik?Westerholm 《Journal of Soils and Sediments》2002,2(4):194-202
Background Petroleum products are widely used in various sections of industry and they are one of the most abundant sources of environmental
contamination. These products are classified by their physico-chemical properties such as boiling point, density and viscosity.
Oil contamination in the environment is primarily evaluated by measuring the chemical concentrations of petroleum products
in the solid or water phase. The results of chemical analyses do not correspond directly with the harmful environmental effects
of petroleum products on the soil flora and fauna, because the interactions between oil compounds and the production of their
methabolites in soil are not measured in chemical assessments. These kinds of effects of complex chemical mixtures in soil
can be estimated by bioassays. Therefore, ecotoxicological tests are important for estimating soil quality in the risk assessment
of oil-contaminated soil sites.
Objectives The objective of this study was to examine the oil-contaminated soil site of a closed petrol station with both chemical and
ecotoxicological methods. The goals of this study were to compare the sensitivity of the terrestrial and aquatic bioassays
and to compare the toxicity responses of aquatic bioassays determined from three different extraction procedures. In addition,
our aim was to characterise a cost-effective battery of bioassays that could be applied to a comparison of oil-contaminated
soils. It was in our interest to investigate oil-contaminated soil with oil concentrations of 2500–12000 mg/kg and to find
out the possible differences between terrestrial and aquatic toxicity tests.
Methods Six soil samples from a closed petrol station were examined for toxicity with terrestrial and aquatic tests. Terrestrial tests
includedEnchytraeus albidus survival and reproduction assays and seed germination assays using wheat, cress, lettuce, and red clover seeds and growth
inhibition assays of onions. The toxicities of the water-extractable fractions of the soil samples obtained from three different
extractions were tested with aquatic bioassays based on plants (onion and duckweed growth inhibition tests), microbes (luminescent
bacteria test), and enzyme inhibition (reverse electron transport test, RET). Chemical analyses of the solid samples were
carried out simultaneously. Results. Oil concentrations ranged from 2500 to 12000 mg/kg, BTEX varied from 300 to 2800 mg/kg,
and fuel additives: MTBE and TAME from 0.0 1 to 260 mg/kg. Only the sample contain-ing 12000 mg/kg oil had a significant toxic
impact on all test organisms. Soil samples with oil concentrations 2500–6200 mg/ kg had no or only slight adverse effects
on the test organisms with one exception, theE. albidus reproduction test. TheE. albidus survival and reproduction tests were the most sensitive bioassays of the terrestrial tests, and the luminescent bacteria
test of the aquatic tests. 相似文献
107.
Bertram HC Jakobsen HJ Andersen HJ Karlsson AH Engelsen SB 《Journal of agricultural and food chemistry》2003,51(7):2064-2069
Solid-state (13)C cross-polarization (CP) magic-angle spinning (MAS) nuclear magnetic resonance (NMR) experiments are carried out for the first time on rapidly frozen muscle biopsies taken in M. longissimus in vivo and at 1 min, 45 min, and 24 h post-mortem from three pigs. Two of the pigs were CO(2)-stunned (control animals), and one was pre-slaughter-stressed (treadmill exercise) followed by electrical stunning to induce difference in metabolism post-mortem. (13)C resonance signals from saturated and unsaturated carbons in fatty acids, carboxylic carbons, and carbons in lactate and glycogen are identified in the solid-state NMR spectra. The (13)C CP MAS spectra obtained for post-mortem samples of the stressed, electrically stunned pig differ significantly from the post-mortem control samples, as the intensity of a resonance line appearing at 30 ppm, assigned to carbons of the methylene chains, is reduced for the stressed pig. This spectral difference is probably due to changes in lipid mobility and indicates altered membrane properties in the muscle of the stressed/electrically stunned animal when compared with the control animals already 1 min post-mortem. In addition, the post-mortem period changes in glycogen carbons can be estimated from the (13)C CP MAS spectra, yielding a correlation of r = 0.74 to subsequent biochemical determination of the glycogen content. 相似文献
108.
The recent decline of the European starling in northern Europe has been associated with changes in agricultural land-use. We investigated how agricultural land-use affected starling habitat use and home-range size in a heterogeneous landscape in southern Sweden. Breeding starlings primarily foraged in pastures, a habitat with a high availability of potential food for nestlings. When the availability of pasture close to the nest was low, starlings increased their use of other permanently grass-covered habitats such as field margins and ditches. They also spent a larger proportion of their daytime flying because they visited more distant foraging areas. The further from the nest parents foraged, the higher was the probability that they foraged on a pasture. Feeding frequency of nestlings was negatively related to the distance from the nest parents foraged, but no consequences on nestling survival or growth were found. A lower breeding density at low local availability of pasture may compensate for lack of good foraging habitat. It is suggested that recent changes in the agricultural landscape may have increased the mismatch between the availability of good foraging areas and nest-sites. This might have contributed to the recent population decline of the starling in northern Europe by affecting both foraging habitat quality and flight costs paid by parents during breeding. 相似文献
109.
Guillaume Laberge Per Ambus Henrik Hauggaard-Nielsen Erik Steen Jensen 《Soil biology & biochemistry》2006,38(7):1998-2000
The decline of N from 15N-labelled mature pea residues was followed in unplanted soil over 16.5 yr. Eight years after residue incorporation, 24% of the residue 15N input was still present in the soil and, after 16.5 yr, 16% of the residue 15N input remained. A double exponential model successfully described the decay of N from 15N-labelled pea residues. The total residual 15N declined with average decay constants of 1.45 yr−1 for the 30 d to 1 yr period and of 0.07 yr−1 for the 1-16 yr period. Sixteen years following incorporation of the residues, indicator plants growing in residues-amended soils were obtaining 1.7% of their N from residue N. This is, to our knowledge, the longest study on decay of N in soils from 15N-labelled crop residues. The current study thus provides a unique data set for our empirical understanding of N-dynamics in agricultural systems, which is a prerequisite to parameterize and validate N-simulation models. 相似文献
110.
Mette E Fertner Rikke H Olsen Magne Bisgaard Henrik Christensen 《Acta veterinaria Scandinavica》2011,53(1):56