Publications by authors named "Tatyana Sidorova"

Globally, grasslands are shaped by grazing and fire, and grassland plants are adapted to these disturbances. However, temperate grasslands have been hotspots of land-use change, and how such changes affect interrelations between herbivory, fire and vegetation are poorly understood. Such land-use changes are widespread on the Eurasian steppe, where the dissolution of the Soviet Union in 1991 triggered the abandonment of cropland and pasture on globally relevant scales.

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In order to achieve the optimal number of colony forming units and a high level of antifungal metabolites synthesis, we carried out the periodic cultivation of the BZR 336 g and BZR 517 strains at various pH and temperature levels. In the experiment for determining the optimal temperature, the maximum titer of BZR 336 g bacterium (1.6-1.

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Cell-cell communication through gap junctions is aberrant or absent in a majority of human cancer cells, compared to cells in corresponding normal tissues. This and other evidence has led to the hypothesis that gap junction channels, comprised of connexin proteins, are important in growth control and cancer progression. The major goal of this ongoing study was to identify bioactive compounds that specifically upregulate gap junction channel-mediated cell-cell communication as potential anti-tumor therapies.

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Chaetoglobosin K (ChK) is a natural product that inhibits anchorage-dependent and anchorage-independent growth of ras-transformed cells, prevents tumor-promoter disruption of cell-cell communication, and reduces Akt activation in tumorigenic cells. This study demonstrates how ChK modulates the JNK pathway in ras-transformed and human lung carcinoma cells and investigates regulatory mechanisms controlling ChK's effect on the Akt and JNK signaling pathways. Human lung carcinoma and ras-transformed epithelial cell lines treated with ChK or vehicle for varying times were assayed for cell growth or extracted for total proteins for western blot analysis using phosphorylation site-specific antibodies to monitor changes in activation of JNK, Akt, and other signaling enzymes.

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Human lung neoplasms frequently express mutations that down-regulate expression of various tumor suppressor molecules, including mitogen-activated protein kinases such as p38 MAPK. Conversely, activation of p38 MAPK in tumor cells results in cancer cell cycle inhibition or apoptosis initiated by chemotherapeutic agents such as retinoids or cisplatin, and is therefore an attractive approach for experimental anti-tumor therapies. We now report that 4-phenyl-3-butenoic acid (PBA), an experimental compound that reverses the transformed phenotype at non-cytotoxic concentrations, activates p38 MAPK in tumorigenic cells at concentrations and treatment times that correlate with decreased cell growth and increased cell-cell communication.

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Purpose: The purpose of the present study was to identify the biochemical mechanism(s) of the preventative and reversal effects of Chaetoglobosin K (ChK), a bioactive natural product, on inhibition of gap junction-mediated communication and connexin phosphorylation by the tumor promoting organochlorine compounds, lindane, and dieldrin.

Materials And Methods: A fluorescent dye transfer assay was used to quantify gap junction-mediated communication and sensitivity to lindane and dieldrin. Analyses of connexin 43, PKC, ERK, GSK-3beta, Raf, and Akt kinase phosphorylation were performed by Western blotting.

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Context: Despite its benign, natural course, colic is a significant problem in infants and imparts a psychological, emotional, and physical burden to parents. Dicyclomine hydrochloride is the only pharmacological treatment for infantile colic that has been consistently effective. Unfortunately, 5% of infants treated with dicyclomine hydrochloride develop serious side effects, including death.

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Multidrug resistance (MDR) mediated by P-glycoprotein (Pgp) remains the major obstacle for successful treatment of cancer. Inhibition of Pgp transport is important for higher efficacy of anticancer drugs. Lipophilic cationogenic amines with at least one tertiary N atom, such as verapamil, are classical PgP-blocking agents.

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