Effect of Cytochalasin B, Lantrunculin B, Colchicine, Cycloheximid, Dimethyl Sulfoxide and Ion Channel Inhibitors on Biospeckle Activity in Apple Tissue

The biospeckle phenomenon is used for non-destructive monitoring the quality of fresh fruits and vegetables, but in the case of plant tissues there is a lack of experimentally confirmed information about the biological origin of the biospeckle activity (BA). As a main sources of BA, processes associated with the movement inside the cell, such as cytoplasmic streaming, organelle movement and intra- and extracellular transport mechanisms, are considered. The aim of this study is to investigate the effect of metabolism inhibitors, connected with intracellular movement such as cytochalasin B, lantrunculin B, colchicine, cycloheximid, dimethyl sulfoxide (DMSO) and mixture of ion channel inhibitors, injected into apples, on BA. Two methods of BA analysis based on cross-correlation coefficient and Laser Speckle Contrast Analysis (LASCA) were used. DMSO, lantrunculin B and mixture of ion channel inhibitors have a significant effect on BA, and approximately 74 % of BA of apple tissue is potentially caused by biological processes. Results indicate that the functioning of actin microfilaments and ion channels significantly affect BA.     

Raman imaging of changes in the polysaccharides distribution in the cell wall during apple fruit development and senescence

Planta - Du ring on-tree ripening, the pectin distribution changed from polydispersed in cell wall to cumulated in cell wall corners. During apple storage, the pectin distribution returned to...     

Expression of p21 and bcl-2 proteins and p53 mRNA in surgically resected preparations of non-small cell lung cancer (stage IIIA) after etoposide and cisplatin chemotherapy

Apoptosis which is also a called programmed cell death plays an important role during development, homeostasis and in many diseases such as cancer. Apoptosis is a genetically encoded cell death program defined by characteristic morphological and biochemical features. It is well recognized as a distinct pathologic mechanism in tumours responding to anticancer therapies. Many genes play an important role in this process. We evaluated an expression of the tumour supressor gene p53 and proteins p21 and bcl-2 in non-small cell lung cancer. We examined resected tumour tissues from 30 patients who received neoadjuvant chemotherapy. As a control we assessed tissues from patients treated without chemotherapy. Histological slides of the resected tumours were evaluated by TUNEL, in situ hybridisation and with immunoperoxidase staining procedure. The results were documented by photography. We examined the level of extinction using cytophotometry. In conclusion, preoperative chemotherapy induces apoptosis in cancer cells. The level of p53 correlates with the acceleration of TUNEL reaction. The loss of bcl-2 expression correlated with an increased apoptotic cell death. There was an increased p21 protein expression in the examined cancer tissues after chemotherapy.     

Multilayer nonnegative matrix factorization using projected gradient approaches

The most popular algorithms for Nonnegative Matrix Factorization (NMF) belong to a class of multiplicative Lee-Seung algorithms which have usually relative low complexity but are characterized by slow-convergence and the risk of getting stuck to in local minima. In this paper, we present and compare the performance of additive algorithms based on three different variations of a projected gradient approach. Additionally, we discuss a novel multilayer approach to NMF algorithms combined with multi-start initializations procedure, which in general, considerably improves the performance of all the NMF algorithms. We demonstrate that this approach (the multilayer system with projected gradient algorithms) can usually give much better performance than standard multiplicative algorithms, especially, if data are ill-conditioned, badly-scaled, and/or a number of observations is only slightly greater than a number of nonnegative hidden components. Our new implementations of NMF are demonstrated with the simulations performed for Blind Source Separation (BSS) data.     

Photochemistry of dyes and fluorochromes used in biology and medicine: some physicochemical background and current applications

An overview of the basic principles of photochemistry is presented to facilitate discussion of fluorescence, quenching and quantum yields. These topics in turn provide the foundation for an account of fluorescence spectroscopy and its application to microscopy. A brief overview of light microscopy and the application of fluorescence microscopy is given. The influences of molecular features, such as aromatic character and substitution patterns, on color and fluorescence are described. The concept of color fading is considered with particular reference to its effect on microscopic preparations. A survey of representative fluorescent probes is provided, and their sensitivity, application, and limitations are described. The phototoxicity of fluorescent molecules is discussed using biomembranes and DNA as examples of targets of toxicity. Photodynamic therapy, a relatively new clinical application of phototoxicity, is described. Both anticancer and antimicrobial applications are noted, and an assessment is given of the current ideas on the ideal physicochemical properties of the sensitizing agents for such applications.     

Quantitative determination of albumin in urine by on-line immunoadsorptive cleanup and reversed-phase chromatography

Albumin in urine is selectively adsorbed on an immunoadsorber (human serum albumin-specific antibodies coupled covalently with a silica stationary phase) and after elution with 0.1% HCl is quantitatively determined by reversed-phase chromatography with detection of native fluorescence. The optimization of sample preparation and characteristics of the method such as recovery, linearity, reproducibility, detection limit, and selectivity are discussed.