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1.
Similar to adult chick sera in chick embryo sera the enzyme activity hydrolyzing the core of the dimer of A-5A - adenylyl(2' -5')adenosine is present. The enzyme activity possesses the same properties in both sera. Heating of the serum to 60 degrees C for 30 minutes does not affect the enzyme activity. A marked decrease in activity occurs after heating of the serum to above 65 degrees C. Hydrolysis of A2' p5' A in the serum is more efficient under alkaline conditions (pH 9-10) than at physiological pH 7.2-7.4. 相似文献
2.
Ovine and caprine scrapie occupies a unique place among animal transmissive spongiform encephalopathies (TSE). It is an object
of intensive biomedicinal, ecological and economical studies. Its causative agents are demonstrably associated with the development
of TSE in farmed minks, goats and moufflons. Ovine strains of scrapie occurring in North America (particularly in the USA)
differ from strains which occur in Europe and were present at the onset of development of TSE in three species of deer living
in free nature and in captivity in the USA. The studies dealing with the development of bovine spongiform encephalopathy (BSE)
of the English type have indicated justifiably that its origin is associated with one (or more) heretofore unidentified ovine
strain. The development of a variant form, the Creutzfeldt-Jacob disease in humans, and transmission of the BSE agent to several
families of bovidae, felidae and primates, puts stress on its zoonotic potential. All this leads to the conclusion that domesticated
sheep are the decisive reservoir species of animal TSE. They have been infected to an unknown extent with the causative agent
of BSE probably through contaminated meat-bone meal. The occurrence of natural ovine prion isolates with properties similar
to those of the BSE agent requires that scrapie should be included in the surveillance of human and animal TSE. At present,
scrapie is a noticeable disease also in other thanEuropean Communities Member States. It is on the list B of theInternational Epizootics Office. Many countries have initiated control of ovine scrapie. It should therefore become a topical question also in Central and
Eastern European countries. Elimination or even eradication of ovine scrapie (or its causative agents) from populations of
small and large domestic ruminants is the prerequisite for prevention of penetration of ovine pathogenic prions into the human
feed chain. Moreover, it should be ensured that these species will be able to produce foods of a new type (immunotrition and
similar) or proteins with therapeutic effects in the near future. Our study established that the PrP genotype of Valachian
rams, the Slovak autochthonous breed, contains also VRQ and ARQ alleles encoding the susceptibility to scrapie. Their selection
is part of the improvement of Slovak Valachian sheep towards resistance to scrapie. 相似文献
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Karl W Kuschner Dariya I Malyarenko William E Cooke Lisa H Cazares OJ Semmes Eugene R Tracy 《BMC bioinformatics》2010,11(1):177
Background
Time-of-flight mass spectrometry (TOF-MS) has the potential to provide non-invasive, high-throughput screening for cancers and other serious diseases via detection of protein biomarkers in blood or other accessible biologic samples. Unfortunately, this potential has largely been unrealized to date due to the high variability of measurements, uncertainties in the distribution of proteins in a given population, and the difficulty of extracting repeatable diagnostic markers using current statistical tools. With studies consisting of perhaps only dozens of samples, and possibly hundreds of variables, overfitting is a serious complication. To overcome these difficulties, we have developed a Bayesian inductive method which uses model-independent methods of discovering relationships between spectral features. This method appears to efficiently discover network models which not only identify connections between the disease and key features, but also organizes relationships between features--and furthermore creates a stable classifier that categorizes new data at predicted error rates. 相似文献5.
Avian and mammalian sera were found to contain an enzyme activity degrading 2-5A oligonucleotides. The most extensive degradation of the A2' p5' A was observed in chicken serum. Degradation of this compound is not affected by the presence of cAMP, dsRNA, Mg2+, but is significantly inhibited by EDTA. The enzyme activity described is not inactivated by heating to 56 degrees C for 30 min. The 5-mU3' p5' A has also been degraded in chicken serum. 相似文献
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Arshad Desai Elizabeth A Holleran Serge Roche Rein Aasland Robert OJ Weinzierl Elisa Izaurralde Karl Matter Paul A Slesinger Martin Pfaff Neil Huckriede Robert A Sclafani 《Current opinion in cell biology》1999,11(6):641
A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in cell biology. 相似文献
8.
Anne Ridley Serge Roche Rein Aasland Robert OJ Weinzierl Elisa Izaurralde Elisabeth Dawson Neil Hukriede Robert L Dorit 《Current opinion in genetics & development》1999,9(6):609
A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in genetics and development. 相似文献
9.
Robert OJ Weinzierl 《BMC biology》2010,8(1):134
Background
Cellular RNA polymerases (RNAPs) are complex molecular machines that combine catalysis with concerted conformational changes in the active center. Previous work showed that kinking of a hinge region near the C-terminus of the Bridge Helix (BH-HC) plays a critical role in controlling the catalytic rate. 相似文献10.