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The diagnosis and treatment of prostate cancer (PCa) is a major health-care concern worldwide. This cancer can manifest itself in many distinct forms and the transition from clinically indolent PCa to the more invasive aggressive form remains poorly understood. It is now universally accepted that glycan expression patterns change with the cellular modifications that accompany the onset of tumorigenesis. The aim of this study was to investigate if differential glycosylation patterns could distinguish between indolent, significant, and aggressive PCa. Whole serum N-glycan profiling was carried out on 117 prostate cancer patients’ serum using our automated, high-throughput analysis platform for glycan-profiling which utilizes ultra-performance liquid chromatography (UPLC) to obtain high resolution separation of N-linked glycans released from the serum glycoproteins. We observed increases in hybrid, oligomannose, and biantennary digalactosylated monosialylated glycans (M5A1G1S1, M8, and A2G2S1), bisecting glycans (A2B, A2(6)BG1) and monoantennary glycans (A1), and decreases in triantennary trigalactosylated trisialylated glycans with and without core fucose (A3G3S3 and FA3G3S3) with PCa progression from indolent through significant and aggressive disease. These changes give us an insight into the disease pathogenesis and identify potential biomarkers for monitoring the PCa progression, however these need further confirmation studies.  相似文献   
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Symbolic parametrization of curves   总被引:1,自引:0,他引:1  
If algebraic varieties like curves or surfaces are to be manipulated by computers, it is essential to be able to represent these geometric objects in an appropriate way. For some applications an implicit representation by algebraic equations is desirable, whereas for others an explicit or parametric representation is more suitable. Therefore, transformation algorithms from one representation to the other are of utmost importance.We investigate the transformation of an implicit representation of a plane algebraic curve into a parametric representation. Various methods for computing a rational parametrization, if one exists, are described. As a new idea we introduce the concept of working with classes of conjugate (singular or simple) points on curves. All the necessary operations, like determining the multiplicity and the character of the singular points or passing a linear system of curves through these points, can be applied to such classes of conjugate points. Using this idea one can parametrize a curve if one knows only one simple point on it. We do not propose any new method for finding such a simple point. By classical methods a rational point on a rational curve can be computed, if such a point exists. Otherwise, one can express the coordinates of such a point in an algebraic extension of degree 2 over the ground field.  相似文献   
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We have analysed trends in male:female ratios among newborns between 1950 and 1990 in 29 countries from five continents. The numbers of liveborn males and females over the period 1950-1994 were derived from the World Health Organization (WHO) database. Countries for which reliable data were available included 20 major European countries (excluding the former Soviet Union, Albania and a few small countries), Canada, the USA, selected countries of Central and South America, Japan, Australia and New Zealand. From the original numbers of males and females, we computed the proportion of males among liveborns for each country and for selected broader areas within Europe. In most countries the proportion of male liveborns was constant during the study period. In particular, the proportion of male newborns in the European Union was 0.515 in 1950-1954, 0.514 in 1970-1974 and 0.514 in 1990-1994. In the USA, corresponding values were 0.513, 0.513 and 0.512. In Japan the ratios were 0.513 in 1950-1954, 0.516 and 1970-1974 and 0.514 in 1990-1994. Decreasing ratios were observed in some northern and eastern European countries plus Greece and Portugal and, particularly, in Mexico. In contrast, the proportion of male liveborns tended to increase in southern Europe and Australia. Overall, among the 29 countries considered, the proportion of males declined in 16, increased in six, and remained stable in seven.  相似文献   
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