Search results for " space"

Direct determination of intracellular daunorubicin in intact confluent monolayers of AT1 prostate carcinoma cells using a multiwell–multilabel counter

2008

The cytostatic drug daunorubicin exerts its toxic action by intercalating into the DNA. The efficacy of daunorubicin depends on the intracellular amount in the tumor cell. Here we have evaluated the use of a multiwell-multilabel reader for the direct determination of the fluorescent cytostatic drug daunorubicin in a prostate carcinoma cell line (AT1 R-3327 Dunning prostate carcinoma cells) grown on 24-well plates. We present evidence that this simple fluorescent parameter is a good measure for the toxicologically relevant amount of the drug intercalated into the DNA and, therefore, is a good predictor for the drug's cytotoxicity. The amount of cationic cytostatics in a tumor cell is primari…

The Odyssey of Hsp60 from Tumor Cells to Other Destinations Includes Plasma Membrane-Associated Stages and Golgi and Exosomal Protein-Trafficking Mod…

2012

BACKGROUND: In a previous work we showed for the first time that human tumor cells secrete Hsp60 via exosomes, which are considered immunologically active microvesicles involved in tumor progression. This finding raised questions concerning the route followed by Hsp60 to reach the exosomes, its location in them, and whether Hsp60 can be secreted also via other mechanisms, e.g., by the Golgi. We addressed these issues in the work presented here. PRINCIPAL FINDINGS: We found that Hsp60 localizes in the tumor cell plasma membrane, is associated with lipid rafts, and ends up in the exosomal membrane. We also found evidence that Hsp60 localizes in the Golgi apparatus and its secretion is prevent…

Hsp60 is actively secreted by human tumor cells

2010

Background Hsp60, a Group I mitochondrial chaperonin, is classically considered an intracellular chaperone with residence in the mitochondria; nonetheless, in the last few years it has been found extracellularly as well as in the cell membrane. Important questions remain pertaining to extracellular Hsp60 such as how generalized is its occurrence outside cells, what are its extracellular functions and the translocation mechanisms that transport the chaperone outside of the cell. These questions are particularly relevant for cancer biology since it is believed that extracellular chaperones, like Hsp70, may play an active role in tumor growth and dissemination. Methodology/Principal Findings S…

The Functional Role of the Second NPXY Motif of the LRP1 β-Chain in Tissue-type Plasminogen Activator-mediated Activation of N-Methyl-D-aspartate Rec…

2008

The low density lipoprotein receptor-related protein 1 (LRP1) emerges to play fundamental roles in cellular signaling pathways in the brain. One of its prominent ligands is the serine proteinase tissue-type plasminogen activator (tPA), which has been shown to act as a key activator of neuronal mitogen-activated protein kinase pathways via the N-methyl-D-aspartate (NMDA) receptor. However, here we set out to examine whether LRP1 and the NMDA receptor might eventually act in a combined fashion to mediate tPA downstream signaling. By blocking tPA from binding to LRP1 using the receptor-associated protein, we were able to completely inhibit NMDA receptor activation. Additionally, inhibition of …

Biogenesis of the Yeast Cell Wall

1984

Yeast cells are covered by a rigid structure that protects the protoplast from osmotic changes and gives the characteristic shape to the cell. Studies on the composition of the wall of several species of yeast and other fungi have shown that they contain mainly polysaccharides with minor amounts of other materials. A completely rigid and continuous wall, nevertheless, would render growth impossible because cell extension would be restricted, so that an equilibrium must exist between softening (partial degradation) of wall and incorporation of new material into free ends of the polymers. From these considerations, it seems clear that the walls must be structurally and enzymatically a complex…

Morphology of follicle cells of Libellulidae (Odonata)

2011

In libellulids, mature oocyte size varies within and between individual ovaries. The regulating mechanism is not yet understood. Variations in the contents of the follicle cells, and thereby their ability to secrete material into the oocyte, might explain some of the observed differences in oocyte size. We therefore investigated the follicle cell surface, the interstitial space width between follicle cells and between follicle cells and oocytes, the number of nuclei, and the cell compartment proportions using scanning and transmission electron microscopy. In all investigated species, the follicle cells were covered by a basal lamina. We found cytoplasmic microvilli and septate junctions. As…

Triatomine vectors of Trypanosoma cruzi: a molecular perspective based on nuclear ribosomal DNA markers.

2002

Chagas disease (American trypanosomiasis) is mainly transmitted by blood-sucking bugs of the reduviid subfamily Triatominae (Hemiptera: Prosorrhyncha). Control strategies are directed mainly against these insect vectors, as no vaccine is available and, except in the very early stage of infection, there is no effective chemotherapy. Studies of deoxyribonucleic acid (DNA) will lead to major advances in our knowledge of Triatominae and their relationships to Chagas disease transmission, epidemiology and control. Analyses of complete sequences of nuclear genes coding for ribosomal ribonucleic acid (rRNA) (rRNA genes) and spacers furnish significant information at the levels of higher taxons, ge…

Typological and cultural aspects of ceramic assemblages from the early phase of the Late Bronze Age to the Early Iron Age in the Seine basin

2021

Color encoding for polychromatic single-channel optical pattern recognition

2010

The common multichannel system for recognizing colored images is replaced by a color-encoded single-channel system. Amethod inspired by the Munsell color system is used for encoding the different colors as phase and amplitude functions. It is shown that for many practical cases the phase information part of the color code is sufficient for obtaining good results. An implementation based on a liquid-crystal television panel that works in a phase-modulation mode is suggested. Computer simulations that demonstrate the capabilities of the suggested method are given as well as a comparison with previously published multichannel performance.

Nonlinear pattern recognition correlators based on color-encoding single-channel systems.

2004

In color pattern recognition, color channels are normally processed separately and afterward the correlation outputs are combined. This is the definition of multichannel processing. We combine a single-channel method with nonlinear filtering based on nonlinear correlations. These nonlinear correlations yield better discrimination than common matched filtering. The method codes color information as amplitude and phase distributions and is followed by correlations related to binary decompositions. The technique is based on binary decompositions of the red, green, and blue and the hue, saturation, and intensity monochromatic channels of the reference and of the input scene, after which the bin…