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In the present study, extracts of 34 species and varieties of the genus Hypericum were screened for activity against a clinical isolate of methicillin-resistant Staphylococcus aureus, which in addition possessed a multidrug efflux mechanism conferring a high level of resistance to therapeutically useful antibiotics. Thirty-three of the 34 chloroform extracts showed significant activity in a disk diffusion assay, and five extracts had minimum inhibitory concentrations of 64 microg/ml, indicating that this genus has great potential to yield compounds with potent activity against multidrug-resistant bacteria. 相似文献
994.
Sarah I. Jacob Randi Drees Marie E. Pinkerton Ellison M. Bentley Simon F. Peek 《Veterinary ophthalmology》2015,18(2):164-167
A 13‐month‐old Holstein bull was presented for right‐sided exophthalmos. Ophthalmologic examination noted that the animal was visual in both eyes, but that the right pupil was persistently dilated and very sluggish to constrict when stimulated with a bright light and that normal ocular motility was absent. Fundic examination of the right eye was normal as was a complete ophthalmologic examination of the left eye. Radiographs at presentation did not reveal the presence of sinusitis or other skull abnormalities. Initial treatment comprised intravenous antibiotics and anti‐inflammatories for orbital inflammation over a 14‐day period. There was no perceptible change in the appearance or neuro‐ophthalmologic examination of the right eye during hospitalization. The animal was discharged to the owner's care, but 3 weeks later was found recumbent with unilateral strabismus of the left eye and a fixed right pupil. Due to the inability to rise and rapid deterioration, humane euthanasia was performed, and a full postmortem examination, preceded by a MRI, was performed that identified abscesses extending bilaterally through the round foramina obliterating the cavernous sinus region, as well as abscessation of the right mandible, right trigeminal neuritis, right‐sided sinusitis, and right‐sided otitis media. Cavernous sinus syndrome should be considered in cattle with a combination of exophthalmos and neuro‐ophthalmologic abnormalities involving cranial nerves III, IV, V, and VI, whose branches are located within the cavernous sinus. 相似文献
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1. Three bacterial phytases derived from Bacillus, Escherichia coli or Klebsiella were compared with a phytase derived from Aspergillus niger in vitro and in vivo. 2. The in vitro results indicated that Aspergillus, E. coli and Klebsiella phytase displayed their activity optima in an acid pH range while Bacillus phytase did so in neutral pH. 3. The trials also revealed that only Bacillus phytase is more resistant to heat treatments, while E. coli and Klebsiella phytases are more stable against proteolytic inactivation. 4. In vivo phytases derived from Aspergillus, Bacillus, E. coli, Klebsiella or a combination of Bacillus and E. coli improved the utilisation of phosphorus (P balance) significantly to 0.54, 0.54, 0.55, 0.55 or 0.58, respectively, compared to 0.42 in the negative control. 5. The phytases used in this study seemed to be equally effective in improving P utilisation regardless of proposed intestinal site of activity. Combination of phytases acting in the gizzard with phytases acting in the intestine seems to be a promising way to further improving in vivo efficacy of phytases in poultry. 相似文献
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999.
Martin J. Attrill David T. Bilton Ashley A. Rowden Simon D. Rundle R. Myles Thomas 《水产资源保护:海洋与淡水生态系统》1999,9(2):237-247
1. The Thames Estuary has a long history of human habitation and industrial development, which has resulted in dramatic losses of foreshore habitat; those fragments of fringing habitats that remain are also under threat from potential encroachment onto the foreshore. This paper describes a survey that set out to document the structural complexity and invertebrate communities of 21 supralittoral sites along a 65 km section of the Thames foreshore, and to assess their conservation value. This is the first extensive survey of supralittoral habitats in an urbanized estuary. 2. Invertebrates were sampled from the supralittoral at each site and the habitat types and their structural complexity (including numbers of plant species) at each site were also documented. The relationships between habitat complexity and invertebrate communities were investigated by linear correlation and multivariate analyses. 3. There were significant positive correlations between the number of supralittoral invertebrate species, habitat complexity (measured as the number of complex habitats present) and the number of plant species at each site. 4. The community composition of supralittoral invertebrates was also related to habitat complexity, although this trend was only evident for species data aggregated to higher taxonomic groups, suggesting that chance may play a key role in the colonization of these fragmented habitats. 5. Based on species recorded, the conservation value of supralittoral sites was low; most taxa were widespread eurytopics and only one supralittoral site (Syon Park) contained a threatened species, the snail Perforatella rubiginosa. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
1000.
The irritant and repellent effects of two organophosphate insecticides, diazinon and chlorpyrifos, were examined on adults of the Tasmanian lacewing, Micromus tasmaniae, in the laboratory. Two household pyrethroid sprays were used as positive controls. The organophosphates did not induce a more rapid onset of preening, a more rapid flight from contaminated filter papers or an avoidance response in Petri dishes. A small but statistically significant avoidance of diazinon, but not chlorpyrifos, occurred when M tasmaniae were introduced onto sprayed potted bean plants. It is concluded that these two organophosphates are not intrinsically irritating or repellent to M tasmaniae and any avoidance reaction would not prevent a lethal dose from being obtained. Therefore, a decline in natural populations of M tasmaniae after application of these chemicals is likely to be due to mortality, rather than dispersal. The implications of these results with regard to using this species as a bioindicator are discussed. © 2000 Society of Chemical Industry 相似文献