采用卵子-胚胎移植技术分析研究家畜受精和早期发育

为了阐明家畜受精及早期发育或者输卵管内未受精卵的变化过程,记述了4种卵-胚胎移植方面的研究：①将来自发情黄体期的猪卵母细胞移植到授精动物的输卵管内,可获得受精结果,但将卵移植到已经交配的猪输卵管内会导致多精受精。②把第7~8 d的猪孵化囊胚移植到同期处理的受体内,可以观察到胚胎成功发育到19~23 d。证明失去滋养外胚层的扩张囊胚可以承受移植的物理操作并保持发育能力,而且未交配受体的黄体寿命可以在第7 d和第8 d支持移植胚胎发育。③取2~6 mm直径发育卵泡的牛卵母细胞经体外成熟可以在授精小母牛的输卵管内正常受精,表明其具有受精和胚胎发育能力。④将马的卵母细胞移植到猪的输卵管内,卵母细胞到达子宫的时间仅需46~48 h,在此过程中没有发现未受精马卵的退化现象,暗示了输卵管中存在维持卵子生理机能的因子。综上所述,卵移植是研究家畜早期发育的有效分析技术。     

Biofortification of tomato (Solanum lycopersicum) fruit with the anticancer compound methylselenocysteine using a selenocysteine methyltransferase from a selenium hyperaccumulator

Methylselenocysteine (MeSeCys) is an amino acid derivative that possesses potent anticancer activity in animals. Plants that can tolerate growth on soils with high Se content, known as Se hyperaccumulators, do so by converting inorganic Se to MeSeCys by the enzyme selenocysteine methyltransferase (SMT). A cDNA encoding the SMT from a Se hyperaccumulator was overexpressed in tomato (Solanum lycopersicum). Transgenic plants were provided with selenite or selenate to the roots during fruit development, and liquid chromatography-mass spectrometry was used to show that MeSeCys accumulated in the fruit but not in the leaves. Depending on the transgenic line and Se treatment, up to 16% of the total Se in the fruit was present as MeSeCys. MeSeCys was produced more effectively from selenite on a percentage conversion basis, but greater accumulation of MeSeCys could be achieved from selenate due to its better translocation from the roots. MeSeCys was heat stable and survived processing of the fruit to tomato juice.     

Comparison of acid phosphatases in two genotypes of white clover with different responses to applied phosphate

Two white clover (Trifolium repens L.) genotypes, identified by their differing ability to increase in biomass in response to added phosphorus (P) (high P responder, low P responder) were subjected to P deprivation and examined for differences in root growth, root surface acid phosphatase activity, and soluble and ionically‐bound root cell wall isoform profile. As leaf P levels declined, the high P responder showed a greater increase in biomass allocated to the roots, and highest root surface acid phosphatase activity. However, these differences were not statistically significant. The onset of P deprivation enhanced the intensity of several acid phosphatase isoforms in the P deprived root extracts from both genotypes. After 11 days, one basic isoform (resolved atpH4.5) was enhanced in the cell wall extract, an enhancement that was also observed after 26 days. However, for the soluble isoforms, a temporal separation of response was observed in both genotypes. After 11 days, there was no discernable enhancement of the major staining basic isoform or in the major staining acidic isoform (resolved at pH 8.8) in extracts from P‐deprived roots. After 26 days, these isoforms were enhanced in extracts from P‐derived root tissues. Further, a second acidic isoform could now be discerned as a major staining enzyme in P‐derived root extracts from both genotypes.     

Seminole: A new variety of potato combining good chipping characteristics with good field performance in Alabama,Florida, and North Carolina

Seminole (FL282 or B4469-7) is a new potato variety, named and released by the Research and Farm Departments of Frito-Lay, Inc. Its medium-early tubers are round to oblong with smooth, light cream-buff skin color. The eyes are shallow and pink. It was selected on the Research Farm, Rhinelander, Wisconsin from family line B4469, one of 399 family lines received from the National Potato Breeding Program, Beltsville, Maryland. Tested for its reaction to Verticillium wilt, it was one of the most resistant among 1,190 seedlings. It proved superior to many named and numbered varieties in specific gravity and chip color. In Alabama, Seminole produced relatively high yields of tubers with unusually high specific gravity. Tests in Florida and North Carolina gave similar results. In the South, Seminole is usually 7–10 days earlier than Sebago, and produces higher yields of tubers with higher specific gravity. Unlike Sebago, its tubers separate readily from the vines preventing losses in mechanical harvesting.     

An open-source framework for large-scale,flexible evaluation of biomedical text mining systems

Background

Improved evaluation methodologies have been identified as a necessary prerequisite to the improvement of text mining theory and practice. This paper presents a publicly available framework that facilitates thorough, structured, and large-scale evaluations of text mining technologies. The extensibility of this framework and its ability to uncover system-wide characteristics by analyzing component parts as well as its usefulness for facilitating third-party application integration are demonstrated through examples in the biomedical domain.

Results

Our evaluation framework was assembled using the Unstructured Information Management Architecture. It was used to analyze a set of gene mention identification systems involving 225 combinations of system, evaluation corpus, and correctness measure. Interactions between all three were found to affect the relative rankings of the systems. A second experiment evaluated gene normalization system performance using as input 4,097 combinations of gene mention systems and gene mention system-combining strategies. Gene mention system recall is shown to affect gene normalization system performance much more than does gene mention system precision, and high gene normalization performance is shown to be achievable with remarkably low levels of gene mention system precision.

Conclusion

The software presented in this paper demonstrates the potential for novel discovery resulting from the structured evaluation of biomedical language processing systems, as well as the usefulness of such an evaluation framework for promoting collaboration between developers of biomedical language processing technologies. The code base is available as part of the BioNLP UIMA Component Repository on SourceForge.net.

     

Isolation and identification of canine adenovirus type-2 from the upper respiratory tract of a dog

AIM: To report on the isolation and identification of canine adenovirus type-2 (CAV-2) from a greyhound dog with tracheitis/tonsillitis. METHODS: Virus isolation was performed with Madin and Darby canine kidney (MDCK) cell monolayers using standard virological techniques. The isolated virus was identified by haemagglutination inhibition and serum neutralisation tests. Viral DNA was extracted from infected MDCK cells and subjected to restriction endonuclease analysis using the endonuclease enzymes Bam HI, Bgl II, Eco RI and Hind III. RESULTS: A virus, designated 5 113-87, was isolated in MDCK cells yielding typical cytopathic effect. The virus could be neutralised with a CAV-2 specific reference antiserum and also showed some cross neutralisation with CAV-1 specific reference antiserum. The virus 5 113-87 had a high haemagglutination inhibition titre with CAV-2 antiserum using human group 0 red blood-cells and CAV-1 and CAV-2 reference antisera. This virus also had DNA restriction profiles identical to those of the reference CAV-2 (Toronto A26/61), whereas previously isolated strains of adenovirus from dogs in New Zealand had DNA restriction patterns identical to the prototype CAV-1 strain (Utrecht). CONCLUSION: The findings show that the virus 5 113-87 isolated from the upper respiratory tract of a dog in New Zealand is CAV-2.