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排序方式: 共有97条查询结果,搜索用时 15 毫秒
1.
Praziquantel at dosages of 10, 20 or 100 mg/kg of body weight was evaluated against metacercariae of Nanophyetus salmincola in chinook salmon (Oncorhynchus tshawytscha). Ten salmon were used in each of four treated groups and 10 salmon were nontreated controls. Three wk after treatment, viability of metacercariae was determined by histologic evaluation, and by feeding the salmon to coyotes and subsequently determining the numbers of trematode eggs/g of feces and numbers of N. salmincola recovered at necropsy. Results of the experiment indicated that praziquantel at the dosages and routes of administration used was not effective against metacercariae in chinook salmon. 相似文献
2.
A nerve growth factor-regulated messenger RNA encodes a new intermediate filament protein 总被引:23,自引:7,他引:16
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![点击此处可从《The Journal of cell biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Differential screening of a cDNA library from the PC12 rat pheochromocytoma cell line previously revealed a clone, clone 73, whose corresponding mRNA is induced by nerve growth factor (NGF). Induction parallels NGF-stimulated PC12 differentiation from a chromaffinlike phenotype to a sympathetic neuronlike phenotype. We report that DNA sequence analysis reveals that clone 73 mRNA encodes an intermediate filament (IF) protein whose predicted amino acid sequence is distinct from the known sequences of other members of the IF protein family. The sequence has highest homology with desmin and vimentin and includes the highly conserved central alpha-helical rod domain with the characteristic heptad repeat of hydrophobic residues, but has lower homology in the amino-terminal head and carboxyl-terminal tail domains. The head domain contains a large number of serine residues which are potential phosphorylation sites. The expression of clone 73 in vivo in the nervous system of the adult rat was investigated by in situ hybridization of clone 73 probes to tissue sections. The mRNA is expressed at high levels in ganglia of the peripheral nervous system, including the superior cervical ganglion (sympathetic), ciliary ganglion (parasympathetic), and dorsal root ganglion (sensory). In the central nervous system, motor nuclei of cranial nerves III, IV, V, VI, VII, X, and XII as well as ventral horn motor neurons and a restricted set of other central nervous system nuclei express the clone 73 mRNA. Tissues apart from those of the nervous system did not in general express the mRNA, with only very low levels detected in adrenal gland. We discuss the implications of these results for the mechanism of NGF-induced PC12 cell differentiation, the pathways of neuronal development in vivo, and the possible function of the clone 73 IF protein and its relationship to other IF proteins. 相似文献
3.
Eville Gorham 《Biogeochemistry》1991,13(3):199-239
The history of how aspects of biology, geology and chemistry came together over the past three centuries to form a separate discipline known as biogeochemistry is described under four major headings: metabolic aspects, geochemical aspects, biogeochemical cycles, and the origin of life. A brief chronology of major conceptual advances is also presented. 相似文献
4.
Enterobacteriaceae and Aeromonas hydrophila in Minnesota frogs and tadpoles (Rana pipiens).
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![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
D W Hird S L Diesch R G McKinnell E Gorham F B Martin C A Meadows M Gasiorowski 《Applied microbiology》1983,46(6):1423-1425
In 222 Rana pipiens frogs and 34 tadpoles captured in and near Minnesota, Aeromonas hydrophila and 29 species of Enterobacteriaceae, including yersinia enterocolitica and Salmonella arizonae, were isolated from intestines. The prevalence of members of the family Enterobacteriaceae was lowest in frogs captured in early spring and highest in frogs captured in late summer. 相似文献
5.
The distribution of sodium, potassium and glycinebetaine in shoot tissues of salt-treated Suaeda maritima was examined by semi-micro techniques after extraction into toluene-water. Much higher K/Na ratios were observed in the apical regions and in axillary buds than in more mature, fully vacuolated tissues. The younger tissues also contained very high levels of glycinebetaine. Electron-probe X-ray microanalysis of bulkfrozen and fractured preparations showed higher K/Na ratios and higher levels of sulphur and phosphorus in the cytoplasm of leaf primordial cells than in vacuoles of either young or old leaves, although the total counts were higher in the vacuolar samples. The results are discussed in relation to current models of subcellular solute compartmentation and salt tolerance in the Chenopodiaceae. 相似文献
6.
Distribution of Purple Photosynthetic Bacteria in Wetland and Woodland Habitats of Central and Northern Minnesota
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![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Enrichment cultures for purple nonsulfur and sulfur photosynthetic bacteria were prepared from soil samples collected in central and northern Minnesota. The purple nonsulfur bacteria were found in most wetland soils sampled but were uncommon in woodland and grassland soils. The pH range of the soils in which these bacteria occurred was 3.8 to 7.8, and the oxidation-reduction potential (E(h)) range was +510 to -65 mV. Soils with a pH below 5.0 or an E(h) above +370 mV had few purple nonsulfur bacteria (<10/g of soil). Rhodopseudomonas viridis, a photosynthetic bacterium containing bacteriochlorophyll b, and the purple sulfur bacteria were common only in low-acidity wetland soils that were usually being reduced. 相似文献
7.
Severity of arthritis is predicted by antibody response to gp135 in chronic infection with caprine arthritis-encephalitis virus. 总被引:14,自引:8,他引:6
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![点击此处可从《Journal of virology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Antibody titers to caprine arthritis-encephalitis virus surface glycoprotein gp135 and core protein p28 in synovial fluid and serum from 35 goats infected for 3 years were compared with the histologic severity of arthritis in these animals. Anti-gp135 antibody titers in synovial fluid and serum directly reflect the severity of carpal arthritis in chronically infected goats. 相似文献
8.
The long arm of chromosome 4D of wheat (Triticum aestivum L.) contains a gene (or genes) which influences the ability of wheat plants to discriminate between Na+ and K+. This discrimination most obviously affects transport from the roots to the shoots, in which less Na+ and more K+ accumulate in those plants which contain the long arm of chromosome 4D. Concentrations of Na+ and K+ in the roots, and Cl− concentrations in the roots and shoots, are not significantly affected by this trait, but Na+, K+ and Cl− contents of the grain are reduced. The trait operates over a wide range of salinities and appears to be constitutive. At
the moment it is not possible to determine accurately the effect of this trait on growth or grain yield because the aneuploid
lines which are available are much less vigorous and less fertile than their euploid parents. 相似文献
9.
Richard Wales Hazel C. Gorham Khalid Hussain Lynne M. Roberts J. Michael Lord 《Glycoconjugate journal》1994,11(4):274-281
Deleted forms of ricin B chain (RTB) containing only one of the two galactose binding sites were produced inE. coli and targeted to the periplasm by fusion to theompA orompF signal sequences. The proteins were then isolated from the periplasm and their sugar binding properties assessed. Previous studies investigating the properties of such proteins produced inXenopus laevis oocytes suggested that deleted forms of RTB, when not glycosylated, retain their ability to bind simple sugars, unlike the full-length unglycosylated proteins. When produced inE. coli however we found that only one, EB733, of a number of deleted forms of RTB closely related to those previously produced inXenopus laevis oocytes, bound to simple sugars. All of the deletion forms of RTB were found to bind in the asialofetuin binding assay; an assay which has been previously utilized to measure binding of lectins to the terminal galactose residues of glycoprotein oligosaccharides. However, in contrast to glycosylated RTB, binding of the deletion mutants could be competed to only a small degree or not at all with galactose. The only deletion mutant observed to bind to free galactose when produced inE. coli corresponded closely to the complete domain 2 of RTB. It is assumed that this mutant forms a stable structure similar to that of the C-terminal domain in the full-length protein. The structural integrity of EB733 was not only suggested by its sugar binding properties and solubility but also by its consistently higher level of expression and the absence of any apparent susceptibility toE. coli proteases.Abbreviations RTA
ricin toxin A chain
- RTB
ricin toxin B chain
- ER
endoplasmic reticulum
- SDS-PAGE
sodium dodecyl sulphate-polyacrylamide gel electrophoresis
- IPTG
isopropyl -d-thiogalactopyranoside 相似文献
10.
Caprine Arthritis-Encephalitis Virus Is Distinct from Visna and Progressive Pneumonia Viruses as Measured by Genome Sequence Homology 总被引:5,自引:3,他引:2
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![点击此处可从《Journal of virology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Susan M. Roberson Travis C. McGuire Paula Klevjer-Anderson John R. Gorham William P. Cheevers 《Journal of virology》1982,44(2):755-758
Competitive inhibition of hybridization between 125I-labeled caprine arthritis-encephalitis viral RNA and homologous cDNA by heterologous viral RNA shows that the caprine retrovirus shares <20% genome sequence homology with visna and progressive pneumonia viruses. These viruses, however, are indistinguishable in immunodiffusion reactions involving the major structural protein (p28). 相似文献