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Production and elimination of superoxide radical in relation to the compatibility of snails and trematodes
Cibulková, Lucie ; Skála, Vladimír (advisor) ; Nývltová, Eva (referee)
Almost all trematodes use snails as the intermediate host in their life cycles. To survive within the host, they have to efficiently avoid defense reactions of its immune system. The most important effector cells, haemocytes, produce reactive oxygen species with the first molecule known as superoxide radical. Various snail species produce different levels of these radicals in relation to the compatibility with the invasive trematode species. The parasite decreases the levels of toxic radicals by using antioxidant enzymes including superoxide dismutase which catalyzes transformation of superoxide radical into hydrogen peroxide. This dismutation reaction is the first step during the oxidative burst and likely influences survival of trematodes within the host. Based on the current knowledge the production and elimination of superoxide radical in relation to the compatibility between snails and trematodes have been described thoroughly for a few models such as for example Biomphalaria glabrata-Schistosoma mansoni. However, this interaction appears to play a key role and, therefore, it deserves more attention in another models as well. Key words: trematodes, snails, compatibility, haemocytes, oxidative burst, antioxidant enzymes, superoxide dismutase, superoxide radical
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Production and elimination of superoxide radical in relation to the compatibility of snails and trematodes
Cibulková, Lucie ; Skála, Vladimír (advisor) ; Nývltová, Eva (referee)
Almost all trematodes use snails as the intermediate host in their life cycles. To survive within the host, they have to efficiently avoid defense reactions of its immune system. The most important effector cells, haemocytes, produce reactive oxygen species with the first molecule known as superoxide radical. Various snail species produce different levels of these radicals in relation to the compatibility with the invasive trematode species. The parasite decreases the levels of toxic radicals by using antioxidant enzymes including superoxide dismutase which catalyzes transformation of superoxide radical into hydrogen peroxide. This dismutation reaction is the first step during the oxidative burst and likely influences survival of trematodes within the host. Based on the current knowledge the production and elimination of superoxide radical in relation to the compatibility between snails and trematodes have been described thoroughly for a few models such as for example Biomphalaria glabrata-Schistosoma mansoni. However, this interaction appears to play a key role and, therefore, it deserves more attention in another models as well. Key words: trematodes, snails, compatibility, haemocytes, oxidative burst, antioxidant enzymes, superoxide dismutase, superoxide radical
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Circadian changes of Spodoptera littoralis haemocytes
TREFILOVÁ, Terezie
Abstrakt This work is a study of the morphology of hemocytes and stability of the basic non-pathological hematological levels during 24 hours. Spodoptera littoralis. (Boisd.) (Lepidoptera: Noctuidae) in the sixth instar was used as the biological model. Light microscopy was the technique used to observe the hemocytes. Prior to the microscopy, preparations were made from the hemolymph and stained by Pappenheim's staining method. This is a method which is routinely used in veterinary as well as human laboratory practice in hematology. Six types of hemocytes were observed: small granulocytes (sGR), large granulocytes (lGR), small prohemocytes (sPR), large prohemocytes (lPR), spherulocytes (SP), and plasmatocytes (PL). Pappenheim's staining also enabled apoptosis to be followed. The knowledge of circadian changes in hemocytes in S. littoralis is very important if this animal is to be employed as a new biological model, for instance, for investigations in imunology, hematotoxicology or pharmacotoxicology. Changes in the levels of some substances can be physiological even if lying beyond the reference level limits (Knapp et al., 1984). We found the various hemocyte counts varying throughout the day. At midnight, the sPR and lPR counts are lowest while the apoptotic cell and lGR counts are highest. We tested the use of an ELISA reader (Sunrise, Tecan) (which is based on the photometric principle) with a view to increasing the precision and shortening the time of analysis. However, due to the large spans of concentrations, viz. roughly from 2 mmol/l to 30 mmol/l, the use of the ELISA reader was found unsuitable.
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Examination of changes in fagocytosis for the screening of hemotoxicity on a biomodel
JURČOVÁ, Martina
This thesis dealt with the study of laboratory methods used in the examination of phagocytosis and we conducted the research of the examination of the changes of phagocytosis on the biomodel S. littoralis. The results showed the assumed increase in phagocytosis after the administration of the model substance. Our tests applied documented quite sensitively the changes in fagocytic acitivity and production of cytotoxic substances and the model animal was evaluated as a suitable biomodel for the other studies of hemotoxicity.
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Cytochemická vyšetření akvitivity nukleolů po podání genisteinu na modelovém objektu
PICMONOVÁ, Veronika
This thesis deals with exploration of the effect of genistein on proteosynthetic activity of nucleoli by observing changes in their morphology. The effect of genistein on the function of nucleoli was observed in hemocytes of the experimental animal Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae). 4 types of hemocytes were found in the hemolymph of S. littoralis (Boisduval): granulocytes, prohemocytes, plasmatocytes and spherulocytes. The effect of genistein on individual types and concentration of hemocytes is not clear. Genistein was applied in doses of 0,135 mg and 0,54 mg per larva, and subsequently changes in morphology, number and size of nucleoli were examined upon 8 and 24 hours. Furthermore, changes in morphology of the hemocytes were examined, as well as their concentration using toluidine blue staining, silver staining, panoptic staining and using the Türk{\crq}s solution. For the purpose of changes assessment, the material was processed using an optical microscope and the computer software Nis Element AR 2.30. In the course of observation, changes in the number of nucleoli were found upon application of genistein. The number of compact nucleoli and micronucleoli increased. On the contrary, the number of ring-shaped nucleoli decreased. The area of nucleoli increased upon application of lower dosage of genistein (0,135 mg); however, upon action of the higher dose (0,54 mg), it decreased, on the contrary. Nucleolar index values remained without rather significant changes. In the biomodel used, genistein evoked changes which can be viewed as immune responses from the viewpoint of hematotoxicology.
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