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Biomedical subjects

M Cervinka

Publications and source records attributed to M Cervinka.

At least 19 recordsLinked to original sources
PubMed2004

Sodium salicylate inhibits NF-kappaB and induces apoptosis in PC12 cells.

Sodium salicylate (NaSal) is an effective analgetic and antiinflammatory drug. Beside its well-known inhibitory effect on the cyclooxigenase enzymes, it influences the activity of other signal transduction proteins including nuclear factor kappa B (NF-kappaB) transcription factor. NF-kappaB is found in the cytoplasm bound to an inhibitory protein, inhibitory kappa B (IkappaB). After its phosphorylation, IkappaB is degraded and the released NF-kappaB translocates into the nucleus. Sodium salicylate inhibits the degradation of IkappaB, thus, NF-kappaB activation cannot occur. According to previous observations, the inhibition of this activation can lead to apoptosis. The main goals of this study were to demonstrate that inhibition of NF-kappaB by sodium salicylate decreases the viability of rat phaeochromocytoma PC12 cells and to investigate the nature of cell damage and death. PC12 cells were treated with different concentrations of sodium salicylate (1-20 mM). Higher concentrations (10-20 mM) killed PC12 cells in a dose-dependent manner. The assessments were done by direct cell counting in a Burker chamber and by the WST-1 cytotoxicity assay. We also found a decreased NF-kappaB activity after sodium salicylate treatment by electrophoretic mobility shift assay (EMSA). The cells treated with sodium salicylate were undergoing apoptosis as seen on our records obtained by time-lapse videomicroscopy as well as shown by DNA fragmentation experiments. The decreased DNA binding activity of NF-kappaB indicates that the inhibition of NF-kappaB can play a role in these processes.

Animals↗
PubMed2004

Combined effect of sodium selenite and campthotecin on cervical carcinoma cells.

The effects of selenite, campthotecin and their combination were investigated in cervical carcinoma cell line Hep-2 HeLa during 24h. The measured parameters included morphological changes, proliferation, oxidative stress, mitochondrial status, caspase-3 activation and nuclear fragmentation. Selenite at all but lowest concentrations inhibited cell growth and proliferation and induced cell death characterized by membrane blebbing, oxidative stress and mitochondrial damage, occurring in the absence of caspase-3 activation and nuclear fragmentation. Campthotecin at all concentrations induced gradual apoptosis including all measured morphological and molecular parameters with exception of oxidative stress. A combination of selenite and campthotecin induced both antagonistic and synergistic effects on cervical carcinoma cells. While low selenium concentration slightly reduced cytotoxicity and proapoptotic effects of campthotecin, moderate and higher concentrations of selenium enhanced them, changing simultaneously apoptosis into more necrosis-like death. These results show importance of selenium as a potential modulator and enhancer of campthotecin-based anticancer therapy in nonovarian malignancies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

Topoisomerases and tubulin inhibitors: a promising combination for cancer treatment.

Modern approaches to treatment of cancer seek to activate the internal suicide program in the malignant cells, and thereby effectively eliminate them without engaging most of other bodily systems. Many currently used cytostatics are known to induce apoptosis and efforts are being paid to develop new ones with better and more effective proapoptotic potential. Nevertheless, despite recent developments in this field, there are still numerous malignancies showing a varying degree of resistance to cell death due to the corrupted signaling pathways and genetic alterations, often in conjunction with expansive proliferation rate. It has been shown that topoisomerase inhibiting agents such as etoposide, camptothecin and others represent a powerful and dynamic group of cytostatic chemicals used in experimental and clinical conditions. So, it is a group of microtubule targeting poisons comprising classical colchicines on the one hand and new taxanes on the other hand. Since several members of both groups have been evidenced as apoptosis inducers operating via distinct mechanism, their combination should theoretically enhance the final therapeutic outcome. This minireview focuses on the possibilities of such a combinational approach with respect to possible benefits and hazards of this strategy.

Antineoplastic Agents↗
PubMed2002

3D-computer based reconstructions of apoptotic nuclei.

We present a 3D-model of apoptotic nuclei of HL-60 cells treated with 10 g/ml Etoposide (topoisomerase II inhibitor) for 24 hours. The static model was generated from a series of optical sections obtained through a confocal microscope by freeware and shareware graphical programs available in the Internet. Its animation was done by 3D Studio Max. We demonstrate the appearance of typical fragmentation and condensation of chromatin accompanied by its aggregation to the inner side of the nuclear membrane.

Apoptosis↗
PubMed2001

[Zinc and its role in the regulation of cell death].

Zinc is a key element for maintenance of the structural and functional integrity of eukaryotic cells and tissues. In living systems, it forms stable complexes with macromolecules as well as so called labile pools called zincosomes, which are nowadays considered crucial for the regulation of apoptosis and cell proliferation. Zinc may block apoptosis induced by many external factors by inhibiting caspases and endonucleases, through interactions with transcription factors and kinases or due to its antioxidant activities. On the other hand, depletion of zinc may lead to rapid activation of apoptotic cascade and consequent cell death in many types of cells. Imbalances in intracellular zinc pools lead to improper regulation of cell death and proliferation, which is often causing or accompanying diseases. Therefore, detailed elucidation of the role of zinc in these regulations presents a solution for various pathophysiological conditions.

Apoptosis↗
PubMed2000

Apoptosis - when the cells begin to dance.

We present a 24-hour time-lapse videosequence of in vitro behavior of Hep-2 cells treated with 10 m g/ml Etoposide, a topoisomerase II inhibitor. The cell behavior was recorded by a Mitsubishi video recorder, HS-S5600. In the presented sequence, we show the typical cell rounding accompanied by formation of numerous pseudopodia and rapid rhythmical contractions, so called membrane blebbing known as "dance of death".

Apoptosis↗
PubMed2000

The dynamics of the hexavalent chromium induced apoptotic patterns in vitro.

Although hexavalent chromium has been shown to induce apoptosis in cells cultivated in vitro, there appear to be no studies focusing on the dynamics of this process. To find out about dynamic patterns of hexavalent chromium-induced apoptosis, we treated Hep2 cells with 150 micrograms/ml potassium chromate and recorded their behavior as well as appearance of some crucial organelles using different morphological and biochemical methods. We found that Hep2 cells showed the earliest observable changes at 6 hours after the treatment (blebbing, chromatin shrinkage), with the entire apoptotic process lasting up to 24 hours. While all the observed cell features clearly prove apoptosis induced by hexavalent chromium, a typical apoptotic hallmark, DNA ladder, seems not to occur in this type of cells. On the other hand, in HL60 cells, used as a control, this ladder was observable.

Apoptosis↗
PubMed1999

The role of mitochondria in apoptosis induced in vitro.

Cell death remains the focus of in vitro toxicology. Xenobiotics are capable of bringing about two types of cell death: apoptosis and necrosis. From our previous study we know that cells treated with xenobiotics showed very dynamic changes in their morphology, particularly vigorous movement of the plasma membrane. Such changes probably depend on adequate energy supply. This observation stands in contradiction with published data showing that generation of ATP in mitochondria is altered very early in apoptosis. In this study we analysed the relationship between mitochondrial activity and cell death induced by Etoposide, a selective inhibitor of topoisomerase II, treatment (10 microg/ml). As a model system we used stabilised cell line Hep2. Several markers of apoptosis, including typical cell morphology and DNA ladder formation were measured. The dynamics of morphological changes was recorded by the time-lapse videomicroscopy. We measured mitochondrial membrane potential with a specific fluorochrome DASPMI, quantification was done by microfluorometric assessment. Our data show that mitochondrial activity was maintained during the first 6 hours after the treatment with Etoposide, at the same time substantial changes in cell morphology as well as typical DNA fragmentation were observed.

Apoptosis↗
PubMed1999

[Cytotoxicity tests of stomatologic materials on cell cultures].

Authors compare the benefits and drawbacks of agar diffusion tests (with neutral red and with thiazolyl blue) and the filter diffusion test recommended as the standards for cytotoxicity testing of dental materials and their eluates. It seems that there are no differences between these diffusion tests after the treatment for 24 hours. Authors discuss the observed differences in the toxicity between a solid form of the material (ANA 2000 DUO, Evicrol Solar LC) and its eluate.

Animals↗
PubMed1998

Radiopaque poly(2-hydroxyethyl methacrylate) particles containing silver iodide complexes tested on cell culture.

Silver iodide complexes have been used as an effective radiopacifying agent to prepare radiopaque poly(2-hydroxyethyl methacrylate) (poly(HEMA)) particles. Incorporation of silver iodide complexes inside the poly(HEMA) particles was achieved by first swelling particles in potassium iodide solution and precipitating the silver iodide complexes using a 30 wt% solution of silver nitrate. The dry particles contained 15 wt% of silver iodide complexes. Particles were easily monitored using a standard imaging technique based on X-ray absorption. Toxicity of the particles has been determined in in vitro experiments on a cell culture. As no inhibition of growth of cells surrounding the particles was observed, they can be considered non-toxic.

Biocompatible Materials↗
PubMed1998

Effect of triiodothyronine administration on the recovery of liver oxidative capacity after partial hepatectomy.

The aim of the present work was to investigate the role of triiodothyronine on liver regeneration after partial hepatectomy in the rat. During the first 3 days of liver regeneration, total protein, total DNA content and total cytochrome c oxidase activity of the residual tissue increased from 30% immediately after partial hepatectomy to 70% of the preoperative values in control rats. In triiodothyronine-treated rats, the increase in total protein was the same (70%), however, the increase in total liver DNA content and total cytochrome c oxidase acitivity was 100 and 135%, respectively during the first 3 days of regeneration. Triiodothyronine administration also increased significantly the activity of mitochondrial ATPase in regenerating liver.

Adenosine Triphosphatases↗
PubMed1997

Hydrogels in endovascular embolization. VI. Toxicity tests of poly(2-hydroxyethyl methacrylate) particles on cell cultures.

Cytotoxicity of poly(2-hydroxyethyl methacrylate) [poly(HEMA)] hydrogel spherical particles, prepared by radical suspension polymerization and designed for endovascular occlusion, was studied in vitro on cell cultures. Testing methods included a direct contact test and extraction test. No inhibition of growth of cells surrounding the poly(HEMA) beads and a very low inhibition of cell viability, only in concentrated extracts in long-term contact, were observed. As a result, poly(HEMA) beads can be considered non-toxic.

Biocompatible Materials↗
PubMed1997

[Preparation trauma in stomatology].

In this paper authors deal with the causes of preparation trauma in stomatology. They have studied effects of high temperature on human cells cultured in vitro. Based both on literature data and on their own experience they summarize basic principles of preparation which prevent preparation trauma. They summarize how to eliminate as much as possible factors that damage hard dental tissues and pulp.

Cell Line↗
PubMed1997

[Physical, chemical and biological aspects of treatment of pathological changes in hard dental tissues].

The methods of preparation of dental tissues, treatment of the dentine wound and filling materials, which replace the hard dental tissues, are discussed to evaluate their features in toward the requirements for biological harmlessness. Based on the literature data, their own clinical and practical experiences, the authors have found that none of the currently used preparation methods as well as supports or filling materials are fulfilling the biological treatment requirements. Therefore, it is necessary to be aware of this fact, and adjust the medical procedures in such a way to avoid the harmful effects or to suppress then as much as possible until the ideal preparation procedures and filling materials will be developed.

Dental Caries↗
PubMed1991

Microcinematographic analysis of further fate of multinucleate cells arising after polyethylene glycol induced fusions of L cells.

Cell fusions were studied in continuous cell line L treated with polyethylene glycol (PEG). The progenies of 152 treated cells were studied by time-lapse microcinematography up to four generations. It was found that all the cells that remained mononucleate after treatment with PEG grew actively and their mitotic divisions were without abnormalities. On the contrary, only 60% of multinucleated (fused) cells divided mitotically during the filming period. We observed many disturbances in mitotic divisions of multinucleated cells. In most cases the multipolar divisions of these cells resulted in mononucleate daughters. In half of these cases the daughter cells fused to form again multinucleate cells. Nevertheless, both the total number of multinucleate cells and the average number of nuclei per cell were lowered after mitoses.

Animals↗
PubMed1991

Containers for freezing and storage of bone marrow stem cells.

The authors describe a flat stainless steel container with two necks of the volume 160-180 ml, manufactured according to their own design as well as their first experience with controlled-rate freezing of leukocytes and/or peripheral blood stem cells (PBSC) in this container. The containers meet the requirements of clinical application, i.e. they are made of non-toxic stainless steel, the inner and outer surfaces are polished electrochemically, sterilization by autoclaving is possible, several containers can be frozen simultaneously in a freezing chamber of a programmable freezer and storage of containers in both vapour and liquid phase of nitrogen is possible. Analysis of the cell volume distribution in suspensions of leukocytes and PBSC collected by hemapheresis showed high recovery of cells after thawing. The advantages and disadvantages of metal containers in comparison with disposable plastic bags are discussed in detail.

Bone Marrow↗