11 research outputs found

    Myeloid antigens in childhood lymphoblastic leukemia:clinical data point to regulation of CD66c distinct from other myeloid antigens

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    BACKGROUND: Aberrant expression of myeloid antigens (MyAgs) on acute lymphoblastic leukemia (ALL) cells is a well-documented phenomenon, although its regulating mechanisms are unclear. MyAgs in ALL are interpreted e.g. as hallmarks of early differentiation stage and/or lineage indecisiveness. Granulocytic marker CD66c – Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) is aberrantly expressed on ALL with strong correlation to genotype (negative in TEL/AML1 and MLL/AF4, positive in BCR/ABL and hyperdiploid cases). METHODS: In a cohort of 365 consecutively diagnosed Czech B-precursor ALL patients, we analyze distribution of MyAg+ cases and mutual relationship among CD13, CD15, CD33, CD65 and CD66c. The most frequent MyAg (CD66c) is studied further regarding its stability from diagnosis to relapse, prognostic significance and regulation of surface expression. For the latter, flow cytometry, Western blot and quantitative RT-PCR on sorted cells is used. RESULTS: We show CD66c is expressed in 43% patients, which is more frequent than other MyAgs studied. In addition, CD66c expression negatively correlates with CD13 (p < 0.0001), CD33 (p = 0.002) and/or CD65 (p = 0.029). Our data show that different myeloid antigens often differ in biological importance, which may be obscured by combining them into "MyAg positive ALL". We show that unlike other MyAgs, CD66c expression is not shifted from the onset of ALL to relapse (n = 39, time to relapse 0.3–5.3 years). Although opposite has previously been suggested, we show that CEACAM6 transcription is invariably followed by surface expression (by quantitative RT-PCR on sorted cells) and that malignant cells containing CD66c in cytoplasm without surface expression are not found by flow cytometry nor by Western blot in vivo. We report no prognostic significance of CD66c, globally or separately in genotype subsets of B-precursor ALL, nor an association with known risk factors (n = 254). CONCLUSION: In contrast to general notion we show that different MyAgs in lymphoblastic leukemia represent different biological circumstances. We chose the most frequent and tightly genotype-associated MyAg CD66c to show its stabile expression in patients from diagnosis to relapse, which differs from what is known on the other MyAgs. Surface expression of CD66c is regulated at the gene transcription level, in contrast to previous reports

    Multivariate study of spectral data of oils

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    In this paper the study of structural differences and thermal degradation of edible oils during heating is presented. The study is performed on five types of vegetable oil: extra virgin olive oil, pomace olive oil, sunflower, canola and palm oil. The oils were measured by Raman spectroscopy. This method brings advantages as rapidity, independence on chemicals, provides specific information on chemical composition and structure of material and is able to detect structural changes. For the processing of large data sets multivariate analytical method as Principal component analysis and Cluster analysis are applied to find the patterns within the data. The evaluation of process of thermal degradation is also based on the major decomposition product of oxidized linoleate appearing in spectra via band 1640 cm−1. Mathematically processed data indicate the least effect of heating for olive oils, the greatest degradation and loss of unsaturation for sunflower oil

    Measuring the lactose content in milk

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    Raman spectroscopy has become a powerful and popular tool for food systems analyses lately. Based on characteristic vibrations of the studied material, the information on its content and structure can be answered. In the paper, Raman spectroscopy is studied for a purpose of lactose content in milk assessment. Lactose, the milk disaccharide, in a human organism decomposes during digestion by the act of enzyme lactase to more easily digestible monosaccharides – glucose and galactose. The lack of enzyme lactase causes symptoms of lactose intolerance what limits lactose-intolerant individuals in the intake of milk and dairy products. Lactose-free products in the diet can be a solution. Raman spectroscopy offers rapid measurement independent of the number of chemicals and other in the paper listed benefits. Raman spectra of lactose, glucose and galactose exhibit enough differences to distinguish the content of lactose in milk. C-O-H bending mode at 1087 cm-1 is used for lactose quantification. The method accuracy for measuring content of lactose was tested on dried milk droplets. Evaluation of the spectroscopic data was related to two different substances - phenylalanine contained generally in the milk and crystal violet used as an internal standard

    Punching Shear Failure of Concrete Ground Supported Slab

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    Abstract The article handles potential approaches to design and determination of total load capacity of foundation slabs and floors. The research is focused on punching shear failure of reinforced ground supported slab. The article presents detailed results of the experiment made and advanced numerical modelling based on nonlinear analysis and application of fracture-plastic model. The experiment made included a 2.0 × 1.95 m reinforced concrete slab-on-ground of 120 mm thickness. The experiment was followed by a parametric study of total load capacity calculation with nonlinear analysis which is supplemented by calculations based on existing design model code
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