The Experts below are selected from a list of 45 Experts worldwide ranked by ideXlab platform
Igor Pantic - One of the best experts on this subject based on the ideXlab platform.
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Oxidopamine and oxidative stress: Recent advances in experimental physiology and pharmacology.
Chemico-biological interactions, 2021Co-Authors: Igor Pantic, Jelena Cumic, Sanja Radojevic Skodric, Stefan Dugalic, Claude BrodskiAbstract:Abstract Oxidopamine (6-hydroxydopamine, 6-OHDA) is a toxin commonly used for the creation of experimental animal models of Parkinson’s disease, attention-deficit hyperactivity disorder, and Lesch–Nyhan syndrome. Its exact mechanism of action is not completely understood, although there are many indications that it is related to the generation of reactive oxygen species (ROS), primarily in dopaminergic neurons. In certain experimental conditions, Oxidopamine may also cause programmed cell death via various signaling pathways. Oxidopamine may also have a significant impact on chromatin structure and nuclear structural organization in some cells. Today, many researchers use Oxidopamine–associated oxidative damage to evaluate different antioxidant-based pharmacologically active compounds as drug candidates for various neurological and non-neurological diseases. Additional research is needed to clarify the exact biochemical pathways associated with Oxidopamine toxicity, related ROS generation and apoptosis. In this short review, we focus on the recent research in experimental physiology and pharmacology, related to the cellular and animal experimental models of Oxidopamine - mediated toxicity.
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gray level co occurrence matrix algorithm as pattern recognition biosensor for Oxidopamine induced changes in lymphocyte chromatin architecture
Journal of Theoretical Biology, 2016Co-Authors: Igor Pantic, Draga Dimitrijevic, Dejan Nesic, Danica PetrovicAbstract:We demonstrate that a proapoptotic chemical agent, Oxidopamine, induces dose dependent changes in chromatin textural patterns which can be quantified using the Gray level co-occurrence matrix (GLCM) method. Peripheral blood (heparin-pretreated) samples were treated with Oxidopamine (6-OHDA, 6-hydroxydopamine) to achieve effective concentrations of 100, 200 and 300µM. The samples were smeared on microscope slides and fixated in methanol. The smears were stained using a modification of Feulgen method for DNA visualization. For each stained smear, a sample of 30 lymphocyte chromatin structures were visualized and analyzed. This way, textural parameters for a total of 120 nuclei micrographs were calculated. For each chromatin structure, five different GLCM features were calculated: angular second moment, GLCM entropy, inverse difference moment, GLCM correlation, and GLCM variance. Oxidopamine induced the rise of the values of GLCM entropy and variance, and the reduction of angular second moment, correlation, and inverse difference moment. The trends for GLCM parameter changes were found to be highly significant (p<0.001). These results indicate that GLCM mathematical algorithm might be successfully used in detection and evaluation of discrete early apoptotic structural changes in Feulgen-stained chromatin of peripheral blood lymphocytes that are not detectable using conventional microscopy/cell biology techniques.
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Gray level co-occurrence matrix algorithm as pattern recognition biosensor for Oxidopamine-induced changes in lymphocyte chromatin architecture.
Journal of theoretical biology, 2016Co-Authors: Igor Pantic, Draga Dimitrijevic, Dejan Nesic, Danica PetrovicAbstract:We demonstrate that a proapoptotic chemical agent, Oxidopamine, induces dose dependent changes in chromatin textural patterns which can be quantified using the Gray level co-occurrence matrix (GLCM) method. Peripheral blood (heparin-pretreated) samples were treated with Oxidopamine (6-OHDA, 6-hydroxydopamine) to achieve effective concentrations of 100, 200 and 300µM. The samples were smeared on microscope slides and fixated in methanol. The smears were stained using a modification of Feulgen method for DNA visualization. For each stained smear, a sample of 30 lymphocyte chromatin structures were visualized and analyzed. This way, textural parameters for a total of 120 nuclei micrographs were calculated. For each chromatin structure, five different GLCM features were calculated: angular second moment, GLCM entropy, inverse difference moment, GLCM correlation, and GLCM variance. Oxidopamine induced the rise of the values of GLCM entropy and variance, and the reduction of angular second moment, correlation, and inverse difference moment. The trends for GLCM parameter changes were found to be highly significant (p
Danica Petrovic - One of the best experts on this subject based on the ideXlab platform.
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gray level co occurrence matrix algorithm as pattern recognition biosensor for Oxidopamine induced changes in lymphocyte chromatin architecture
Journal of Theoretical Biology, 2016Co-Authors: Igor Pantic, Draga Dimitrijevic, Dejan Nesic, Danica PetrovicAbstract:We demonstrate that a proapoptotic chemical agent, Oxidopamine, induces dose dependent changes in chromatin textural patterns which can be quantified using the Gray level co-occurrence matrix (GLCM) method. Peripheral blood (heparin-pretreated) samples were treated with Oxidopamine (6-OHDA, 6-hydroxydopamine) to achieve effective concentrations of 100, 200 and 300µM. The samples were smeared on microscope slides and fixated in methanol. The smears were stained using a modification of Feulgen method for DNA visualization. For each stained smear, a sample of 30 lymphocyte chromatin structures were visualized and analyzed. This way, textural parameters for a total of 120 nuclei micrographs were calculated. For each chromatin structure, five different GLCM features were calculated: angular second moment, GLCM entropy, inverse difference moment, GLCM correlation, and GLCM variance. Oxidopamine induced the rise of the values of GLCM entropy and variance, and the reduction of angular second moment, correlation, and inverse difference moment. The trends for GLCM parameter changes were found to be highly significant (p<0.001). These results indicate that GLCM mathematical algorithm might be successfully used in detection and evaluation of discrete early apoptotic structural changes in Feulgen-stained chromatin of peripheral blood lymphocytes that are not detectable using conventional microscopy/cell biology techniques.
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Gray level co-occurrence matrix algorithm as pattern recognition biosensor for Oxidopamine-induced changes in lymphocyte chromatin architecture.
Journal of theoretical biology, 2016Co-Authors: Igor Pantic, Draga Dimitrijevic, Dejan Nesic, Danica PetrovicAbstract:We demonstrate that a proapoptotic chemical agent, Oxidopamine, induces dose dependent changes in chromatin textural patterns which can be quantified using the Gray level co-occurrence matrix (GLCM) method. Peripheral blood (heparin-pretreated) samples were treated with Oxidopamine (6-OHDA, 6-hydroxydopamine) to achieve effective concentrations of 100, 200 and 300µM. The samples were smeared on microscope slides and fixated in methanol. The smears were stained using a modification of Feulgen method for DNA visualization. For each stained smear, a sample of 30 lymphocyte chromatin structures were visualized and analyzed. This way, textural parameters for a total of 120 nuclei micrographs were calculated. For each chromatin structure, five different GLCM features were calculated: angular second moment, GLCM entropy, inverse difference moment, GLCM correlation, and GLCM variance. Oxidopamine induced the rise of the values of GLCM entropy and variance, and the reduction of angular second moment, correlation, and inverse difference moment. The trends for GLCM parameter changes were found to be highly significant (p
John Paul Pezacki - One of the best experts on this subject based on the ideXlab platform.
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Suppressing RNA silencing with small molecules and the viral suppressor of RNA silencing protein p19
Biochemical and biophysical research communications, 2015Co-Authors: Dana C. Danielson, Roxana Filip, Megan H. Powdrill, Shifawn O'hara, John Paul PezackiAbstract:Abstract RNA silencing is a gene regulatory and host defense mechanism whereby small RNA molecules are engaged by Argonaute (AGO) proteins, which facilitate gene knockdown of complementary mRNA targets. Small molecule inhibitors of AGO represent a convenient method for reversing this effect and have applications in human therapy and biotechnology. Viral suppressors of RNA silencing, such as p19, can also be used to suppress the pathway. Here we assess the compatibility of these two approaches, by examining whether synthetic inhibitors of AGO would inhibit p19-siRNA interactions. We observe that aurintricarboxylic acid (ATA) is a potent inhibitor of p19's ability to bind siRNA (IC50 = 0.43 μM), Oxidopamine does not inhibit p19:siRNA interactions, and suramin is a mild inhibitor of p19:siRNA interactions (IC50 = 430 μM). We observe that p19 and suramin are compatible inhibitors of RNA silencing in human hepatoma cells. Our data suggests that at least some inhibitors of AGO may be used in combination with p19 to inhibit RNA silencing at different points in the pathway.
Dana C. Danielson - One of the best experts on this subject based on the ideXlab platform.
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Suppressing RNA silencing with small molecules and the viral suppressor of RNA silencing protein p19
Biochemical and biophysical research communications, 2015Co-Authors: Dana C. Danielson, Roxana Filip, Megan H. Powdrill, Shifawn O'hara, John Paul PezackiAbstract:Abstract RNA silencing is a gene regulatory and host defense mechanism whereby small RNA molecules are engaged by Argonaute (AGO) proteins, which facilitate gene knockdown of complementary mRNA targets. Small molecule inhibitors of AGO represent a convenient method for reversing this effect and have applications in human therapy and biotechnology. Viral suppressors of RNA silencing, such as p19, can also be used to suppress the pathway. Here we assess the compatibility of these two approaches, by examining whether synthetic inhibitors of AGO would inhibit p19-siRNA interactions. We observe that aurintricarboxylic acid (ATA) is a potent inhibitor of p19's ability to bind siRNA (IC50 = 0.43 μM), Oxidopamine does not inhibit p19:siRNA interactions, and suramin is a mild inhibitor of p19:siRNA interactions (IC50 = 430 μM). We observe that p19 and suramin are compatible inhibitors of RNA silencing in human hepatoma cells. Our data suggests that at least some inhibitors of AGO may be used in combination with p19 to inhibit RNA silencing at different points in the pathway.
Dejan Nesic - One of the best experts on this subject based on the ideXlab platform.
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gray level co occurrence matrix algorithm as pattern recognition biosensor for Oxidopamine induced changes in lymphocyte chromatin architecture
Journal of Theoretical Biology, 2016Co-Authors: Igor Pantic, Draga Dimitrijevic, Dejan Nesic, Danica PetrovicAbstract:We demonstrate that a proapoptotic chemical agent, Oxidopamine, induces dose dependent changes in chromatin textural patterns which can be quantified using the Gray level co-occurrence matrix (GLCM) method. Peripheral blood (heparin-pretreated) samples were treated with Oxidopamine (6-OHDA, 6-hydroxydopamine) to achieve effective concentrations of 100, 200 and 300µM. The samples were smeared on microscope slides and fixated in methanol. The smears were stained using a modification of Feulgen method for DNA visualization. For each stained smear, a sample of 30 lymphocyte chromatin structures were visualized and analyzed. This way, textural parameters for a total of 120 nuclei micrographs were calculated. For each chromatin structure, five different GLCM features were calculated: angular second moment, GLCM entropy, inverse difference moment, GLCM correlation, and GLCM variance. Oxidopamine induced the rise of the values of GLCM entropy and variance, and the reduction of angular second moment, correlation, and inverse difference moment. The trends for GLCM parameter changes were found to be highly significant (p<0.001). These results indicate that GLCM mathematical algorithm might be successfully used in detection and evaluation of discrete early apoptotic structural changes in Feulgen-stained chromatin of peripheral blood lymphocytes that are not detectable using conventional microscopy/cell biology techniques.
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Gray level co-occurrence matrix algorithm as pattern recognition biosensor for Oxidopamine-induced changes in lymphocyte chromatin architecture.
Journal of theoretical biology, 2016Co-Authors: Igor Pantic, Draga Dimitrijevic, Dejan Nesic, Danica PetrovicAbstract:We demonstrate that a proapoptotic chemical agent, Oxidopamine, induces dose dependent changes in chromatin textural patterns which can be quantified using the Gray level co-occurrence matrix (GLCM) method. Peripheral blood (heparin-pretreated) samples were treated with Oxidopamine (6-OHDA, 6-hydroxydopamine) to achieve effective concentrations of 100, 200 and 300µM. The samples were smeared on microscope slides and fixated in methanol. The smears were stained using a modification of Feulgen method for DNA visualization. For each stained smear, a sample of 30 lymphocyte chromatin structures were visualized and analyzed. This way, textural parameters for a total of 120 nuclei micrographs were calculated. For each chromatin structure, five different GLCM features were calculated: angular second moment, GLCM entropy, inverse difference moment, GLCM correlation, and GLCM variance. Oxidopamine induced the rise of the values of GLCM entropy and variance, and the reduction of angular second moment, correlation, and inverse difference moment. The trends for GLCM parameter changes were found to be highly significant (p
