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1.
T. V. Vyshenskaya V. P. Tychinsky D. G. Weiss S. A. Kuznetsov 《Biochemistry. Biokhimii?a》2014,79(9):907-916
Dynamic phase microscopy was used to study the dynamic events of formation of the endoplasmic reticulum (ER) in interphase-arrested Xenopus egg extract. We have shown that the ER periodically oscillated in an ATP-dependent manner in the frequency range of 1.6–2.2 Hz, while the tubular membrane network formed in vitro. The spectral density, i.e. the pattern of a given frequency component in the Fourier spectrum, was strongly correlated with the dynamic events during microtubule-dependent and microtubule-independent ER network formation observed by video-enhanced contrast differential interference contrast and fluorescence microscopy. Because the 1.6–2.2 Hz frequency of oscillation during the network formation was detected both in the presence and absence of microtubules, it appears to be an intrinsic ATP-dependent ER membrane property. Several characteristic active and inactive stages of ER network formation were observed both in the presence and absence of microtubules. However, data analysis of these stages indicated that microtubules and dynein motor activity have a strong influence and a cooperative effect on the kinetics of ER formation by controlled fusion reaction. 相似文献
2.
T. V. Vyshenskaya A. A. Bolotova I. A. Vasilenko V. D. Zverzhhovsky D. V. Boldyrev A. V. Kretushev A. A. Evdokimov 《Biophysics》2016,61(3):440-444
A novel technique for the assessment of cytotoxic capacity, which is a characteristic of the state of immune-system cells, has been proposed. Using coherent phase microscopy, perforin granules have been detected and described in the cytoplasm of live CD8+ lymphocytes. According to the analysis of phase images, the parameters of perforin granules in the cell were quantitatively assessed. Their average values were calculated as follows: the projected area on the image plane, 15 ± 7 μm2; phase volume, 0.94 ± 0.24 μm3; and the dry weight of the granules, 0.52 ± 0.11 pg. Taking the advantage of this technique, it appears possible to determine cytotoxic capacity using a small number of live cells without employing fluorescent-labeled probes. 相似文献
3.
Melanoma is the most lethal cutaneous cancer with a highly aggressive and metastatic phenotype. While recent genetic and epigenetic studies have shed new insights into the mechanism of melanoma development, the involvement of regulatory non‐coding RNAs remain unclear. Long non‐coding RNAs (lncRNAs) are a group of endogenous non‐protein‐coding RNAs with the capacity to regulate gene expression at multiple levels. Recent evidences have shown that lncRNAs can regulate many cellular processes, such as cell proliferation, differentiation, migration and invasion. In the melanoma, deregulation of a number of lncRNAs, such as HOTAIR, MALAT1, BANCR, ANRIL, SPRY‐IT1 and SAMMSON, have been reported. Our review summarizes the functional role of lncRNAs in melanoma and their potential clinical application for diagnosis, prognostication and treatment. 相似文献
4.
Visualization of functional properties of individual cells and intracellular organelles still remains an experimental challenge in cell biology. The coherent phase microscopy (CPM) provides a convenient and non-invasive tool for imaging cells and intracellular organelles. In this work, we report results of statistical analysis of CPM images of cyanobacterial cells (Synechocystis sp. PCC 6803) and spores (Bacillus licheniformis). It has been shown that CPM images of cyanobacterial cells and spores are sensitive to variations of their metabolic states. We found a correlation between one of optical parameters of the CPM image (‘phase thicknesses’ Δh) and cell energization. It was demonstrated that the phase thickness Δh decreased after cell treatment with the uncoupler CCCP or inhibitors of electron transport (KCN or DCMU). Statistical analysis of distributions of parameter Δh and cell diameter d demonstrated that a decrease in the phase thickness Δh could not be attributed entirely to a decrease in geometrical sizes of cells. This finding demonstrates that the CPM technique may be a convenient tool for fast and non-invasive diagnosis of metabolic states of individual cells and intracellular organelles. 相似文献
5.
Priscila R Moreira Marcos A Maioli Hyllana CD Medeiros Marieli Guelfi Flávia TV Pereira Fábio E Mingatto 《Biological research》2014,47(1)
Background
The liver is an important organ for its ability to transform xenobiotics, making the liver tissue a prime target for toxic substances. The carotenoid bixin present in annatto is an antioxidant that can protect cells and tissues against the deleterious effects of free radicals. In this study, we evaluated the protective effect of bixin on liver damage induced by carbon tetrachloride (CCl4) in rats.Results
The animals were divided into four groups with six rats in each group. CCl4 (0.125 mL kg-1 body wt.) was injected intraperitoneally, and bixin (5.0 mg kg-1 body wt.) was given by gavage 7 days before the CCl4 injection. Bixin prevented the liver damage caused by CCl4, as noted by the significant decrease in serum aminotransferases release. Bixin protected the liver against the oxidizing effects of CCl4 by preventing a decrease in glutathione reductase activity and the levels of reduced glutathione and NADPH. The peroxidation of membrane lipids and histopathological damage of the liver was significantly prevented by bixin treatment.Conclusion
Therefore, we can conclude that the protective effect of bixin against hepatotoxicity induced by CCl4 is related to the antioxidant activity of the compound. 相似文献6.
Tychinsky VP Kretushev AV Vyshenskaya TV Tikhonov AN 《Biochimica et biophysica acta》2005,1708(3):362-366
Visualization of functional properties of individual cells and intracellular organelles still remains an experimental challenge in cell biology. The coherent phase microscopy (CPM) provides a convenient and non-invasive tool for imaging cells and intracellular organelles. In this work, we report results of statistical analysis of CPM images of cyanobacterial cells (Synechocystis sp. PCC 6803) and spores (Bacillus licheniformis). It has been shown that CPM images of cyanobacterial cells and spores are sensitive to variations of their metabolic states. We found a correlation between one of optical parameters of the CPM image ('phase thicknesses' Deltah) and cell energization. It was demonstrated that the phase thickness Deltah decreased after cell treatment with the uncoupler CCCP or inhibitors of electron transport (KCN or DCMU). Statistical analysis of distributions of parameter Deltah and cell diameter d demonstrated that a decrease in the phase thickness Deltah could not be attributed entirely to a decrease in geometrical sizes of cells. This finding demonstrates that the CPM technique may be a convenient tool for fast and non-invasive diagnosis of metabolic states of individual cells and intracellular organelles. 相似文献
7.
Tychinsky VP Kretushev AV Vyshenskaya TV Tikhonov AN 《Biochimica et biophysica acta》2004,1665(1-2):57-64
Dynamic phase microscopy (DPM) allows the monitoring of optical path difference (or phase height), h(x,y,t) approximately integraln(x,y,z,t)dz, an integral refractive index projection of the medium, n(x,y,z,t), in optically transparent biological specimens at high spatial and temporal resolutions. In this study, DPM was used for the analysis of fluctuations in the optical characteristics of individual bean chloroplasts in various metabolic states. A "phase image" of an individual chloroplast, which represents a three-dimensional plot of the "phase height", was obtained for the first time, and the frequency spectra of the fluctuations of h(x,y,t) were investigated. The fluctuation patterns, i.e., the intensity and the frequency spectra of phase height fluctuations in bean chloroplasts (Class B) were found to depend on their metabolic state. Under conditions of noncyclic (or pseudocyclic) electron transport, the fluctuations displayed characteristic frequencies in the range of 0.25-0.6 Hz and were space-time-correlated in the chloroplast domains with the cross sizes of approximately 2 microm. The fluctuation intensity decreased in the presence of uncouplers (nigericin and valinomycin, 20 microM). A stronger (in comparison with 20 microM valinomycin) effect of 20 microM nigericin suggests that the light-induced generation of the transmembrane pH difference (DeltapH) makes the main contribution to the increment of space-correlated fluctuations of h(x,y,t). Studies of chloroplasts incubated in media of various osmolarity (50-500 mM sucrose) have shown that structural changes in thylakoids are among other factors responsible for phase height fluctuations. 相似文献
8.
V. P. Tychinskii Yu. A. Nikolaev V. V. Lisovskii A. V. Kretushev T. V. Vyshenskaya A. L. Mulyukin N. E. Suzina V. I. Duda G. I. El’-Registan 《Microbiology》2007,76(2):164-171
The changes in the state of Bacillus subtilis spores that occur during germination were analyzed using dynamic phase microscopy (DPM). DPM is based on monitoring and analyzing the interference image of a specimen in a coherent laser beam. The optical path difference (the phase thickness of the specimen, PT) depends on the geometrical height of the specimen and its refractive index. We demonstrated that the maximum PT value is a convenient criterion of the physiological state of the organism involved: PT is ≥ 80 nm, ~40–50 nm, and ≤ 20 in dormant, developing (initiated), and heat-killed spores, respectively. We established that (i) heating a spore suspension to 40°C results in a reversible twofold decrease (from 80 to 40 nm) in their PT under conditions that do not promote the development of the bacteria; this decrease is irreversible under growth-promoting conditions; (ii) the PT values of germinating spores oscillate with a considerable fluctuation amplitude (up to 7 nm), in contrast to the limited fluctuation amplitude (within 1 nm) in dormant spores; (iii) activated spores were heterogenous with respect to the PT pattern: a majority of the spores exhibited a usual spatial profile (with a maximum thickness in the center), whereas a minor fraction of them were characterized by an erythrocyte-like profile with a concave center; this implies that the central zone of the spore was more rapidly hydrated (with a decrease in refractive index) than the peripheral zone. 相似文献
9.
INTRODUCTIONAsearlyasin1948wehavefr8CtionatedisolatednucleifromnormalandtumorcellsbyextractionwithiMNaCIanddilutealkali[1].Thenuclearresiduewasthenstudiedmorethoroughly[2,3].Lateron,sillillarproteinousnuclearresidueswereisolatedbyotherworkers[46]andasstud… 相似文献
10.
Sze SH; Roytberg MA; Gelfand MS; Mironov AA; Astakhova TV; Pevzner PA 《Bioinformatics (Oxford, England)》1998,14(1):14-19
MOTIVATION: Gene annotation is the final goal of gene prediction
algorithms. However, these algorithms frequently make mistakes and
therefore the use of gene predictions for sequence annotation is hardly
possible. As a result, biologists are forced to conduct time-consuming gene
identification experiments by designing appropriate PCR primers to test
cDNA libraries or applying RT-PCR, exon trapping/amplification, or other
techniques. This process frequently amounts to 'guessing' PCR primers on
top of unreliable gene predictions and frequently leads to wasting of
experimental efforts. RESULTS: The present paper proposes a simple and
reliable algorithm for experimental gene identification which bypasses the
unreliable gene prediction step. Studies of the performance of the
algorithm on a sample of human genes indicate that an experimental protocol
based on the algorithm's predictions achieves an accurate gene
identification with relatively few PCR primers. Predictions of PCR primers
may be used for exon amplification in preliminary mutation analysis during
an attempt to identify a gene responsible for a disease. We propose a
simple approach to find a short region from a genomic sequence that with
high probability overlaps with some exon of the gene. The algorithm is
enhanced to find one or more segments that are probably contained in the
translated region of the gene and can be used as PCR primers to select
appropriate clones in cDNA libraries by selective amplification. The
algorithm is further extended to locate a set of PCR primers that uniformly
cover all translated regions and can be used for RT-PCR and further
sequencing of (unknown) mRNA.
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