36 research outputs found
Parasitostatus of red deer population in Eagle mountains (Czech Republic) a results of antiparasitic control
Thesis: Parasitostatus of red deer population in the Eagle Mountains (Czech Republic) and the results of antiparasitic control Made by: Tomáš Filipský The thesis deals with parasitostatus of red deer which is bred in the overwintering enclosures of the Eagle Mountains - Pádolí, Podlesí, Malá Strana. The thesis is aimed at qualitative and quantitative larvoscopic examination of individual anonymous samples of excrement and lungworm species Elaphostrongylus cervi, Varestrongylus sagittatus and Dictyocaulus viviparus. The parasitological examination showed only L1 larvae of Elaphostrongylus cervi the lungworm, the average prevalence of positive findings on the examination was 68.1 % in the winter season 2007/2008. The treatment effectivity was analysed in the overwintering enclosure Pádolí in the winter seasons 2007/2008 and 2008/2009. It achieved the value of 100.0 % in both seasons
Screening of Iron-chelating Substances and their Potential Use in the Therapy of Acute Myocardial Infarction
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department: Department of Pharmacology and Toxicology Candidate: Mgr. Tomáš Filipský First supervisor: prof. MUDr. Radomír Hrdina, CSc. Second supervisor: PharmDr. Přemysl Mladěnka, Ph.D. Title of doctoral thesis: Screening of iron-chelating substances and their potential use in the therapy of acute myocardial infarction Iron is an essential element virtually for all living organisms. The concentration of free/unbound iron is very low at physiological conditions. However, in several pathological states, its homeostasis is impaired which may lead to an organ damage due to the increased production of reactive oxygen species. Coronary heart disease is the main cause of morbidity and mortality worldwide. Its most serious form is acute myocardial infarction (AMI). During the early ischaemia, catalytically active elements, particularly iron and copper, are released into the blood circulation. After restoration of blood flow (reperfusion), these elements may participate in the production of biologically the most potent oxidant - hydroxyl radical via iron/copper catalysed Fenton reaction. Therefore, a therapy based on administration of iron/copper-chelating agents could be a potential pharmacotherapeutic approach in the treatment of this..
Effects of Different Soil Tillage Intensity on Yields of Spring Barley
Within the period 1990–2012, effects of different soil tillage intensity on yields of spring barley were studied in a field experiment in the sugar-beet producing region (Ivanovice na Hané, Czech Republic). The forecrop of the spring barley was always sugar beet; following in three different crop rotations, after maize for silage, winter wheat and spring barley. Four variants of tillage were evaluated: Variant 1 – ploughing to the depth of 0.22 m; Variant 2 – shallow ploughing to the depth of 0.15 m; Variant 3 – no tillage; Variant 4 – shallow loosening soil to the depth of 0.10 m.Effect of different tillage on yields of spring barley was statistically insignificant. In all three crop rotations, the highest and the lowest average yields were obtained in Variant 2 (ploughing to the depth of 0.15 m) and Variant 1 (ploughing to the depth of 0.22 m), respectively. Average yields in variants of soil tillage were these: variant 1 – 6.42 t.ha−1; variant 2 – 6.57 t.ha−1, variant 3 – 6.53 t.ha−1, variant 4 – 6.50 t.ha−1. The obtained results indicate that in these pedo-climatic conditions reduction of intensity soil tillage represented a very suitable alternative in case of growing spring barley after sugar beet as compared with the conventional method of tillage by ploughing to the depth of 0.22 m
Is a Highly Linear Relationship Between the Dose of Quercetin and the Pharmacological Effect Possible? — A Comment on Liu, et al. Evaluation of Antioxidant and Immunity Activities of Quercetin in Isoproterenol-Treated Rats. Molecules 2012, 17, 4281–4291
We wish to offer some comments on the article by H. Liu et al. entitled “Evaluation of antioxidant and immunity activities of quercetin in isoproterenol-treated rats”, published in Molecules in 2012 [1]. [...
Effect of novel 1-phenyl-3-methyl-4-acylpyrazolones on iron chelation and Fenton reaction
Iron is an essential element in many physiological processes due to its ability to easily convert between two oxidation states Fe(III)/Fe(II). However, at a pathological state, unbound iron may promote the production
of highly toxic hydroxyl radicals via Fenton reaction, particularly when it is present in the excess.Iron chelators forming tight complexes with iron may prevent this reaction. In this study, novel synthetic 1-phenyl-3-methyl-4-acyl-pyrazol-5-ones were analyzed for their iron-chelating properties at four pathophysiologically
relevant pH conditions (4.5-7.5) as well as for their effects on iron-based Fenton reaction. For the former competitive ferrozine spectrophotometric assay and for the latter HPLC method using salicylic acid as the indicator of hydroxyl radical production were used. All of the tested acylpyrazolones were efficient ferric chelators,
however, their ferrous-chelating properties were clearly dependent on an acyl substitution. Interestingly, several acylpyrazolones had ferrouschelating properties superior to those of the standard iron chelator – deferoxamine. Of particular interest is H2QpyQ, i.e. 2,6-bis[4(1-phenyl-3-
methylpyrazol-5-one)carbonyl]pyridine, whose ferrous-chelating properties were increasing while pH was decreasing. In spite of large differences in ferrous chelation, a majority of the tested acylpyrazolones were
powerful inhibitors of Fenton reaction as deferoxamine.
In conclusion, the novel 1-phenyl-3-methyl-4-acyl-pyrazol-5-ones are efficient iron chelators and H2QpyQ may represent a prototype of specific iron chelators designed for chelation at acidic conditions in particular
Isoflavones Reduce Copper with Minimal Impact on Iron In Vitro
Isoflavones are commonly consumed in many Asian countries and have potentially positive effects on human being. Only a few and rather controversial data on their interactions with copper and iron are available to date. 13 structurally related isoflavones were tested in the competitive manner for their Cu/Fe-chelating/reducing properties. Notwithstanding the 5-hydroxy-4-keto chelation site was associated with ferric, ferrous, and cupric chelation, the chelation potential of isoflavones was low and no cuprous chelation was observed. None of isoflavones was able to substantially reduce ferric ions, but the vast majority reduced cupric ions. The most important feature for cupric reduction was the presence of an unsubstituted 4′-hydroxyl; contrarily the presence of a free 5-hydroxyl decreased or abolished the reduction due to chelation of cupric ions. The results from this study may enable additional experiments which might clarify the effects of isoflavones on human being and/or mechanisms of copper absorption
In vitro evaluation of copper-chelating properties of flavonoids
Copper is an essential trace element involved in plenty of redox reactions in living systems, however, unbound copper ions cause damage to various biomolecules via excessive generation of reactive oxygen species. Flavonoids, ubiquitous plant secondary metabolites, possess complex effects on human health and chelation of transient metal ions is one of their proposed mechanisms of action. In this in vitro study, 26 flavonoids from various subclasses were screened for their interactions with both copper oxidation states at four (patho)physiologically relevant pH conditions (4.5, 5.5, 6.8 and 7.5) by two spectrophotometric approaches and compared with the clinically used copper chelator trientine. In a slightly competitive environment, the majority of flavonoids were able to chelate cupric ions, however, under more competitive conditions, only flavones and flavonols were able to chelate both cupric and cuprous ions. Apparently, the 2,3-double bond was essential for stable copper chelation. The most efficient copper chelation sites were the 3-hydroxy-4-keto group in flavonols and the 5,6,7-trihydroxyl group in flavones. On the other hand, the 3′,4′-dihydroxyl group was associated only with a weak activity. 3-Hydroxyflavone, kaempferol and partly baicalein were even more potent than trientine in the acidic environment, however, none of the tested flavonoids was able to surpass it at physiological pH or slightly acidic conditions. In conclusion, flavonoids possessing appropriate structural characteristics were efficient copper chelators and some of them were even more potent than trientine under acidic conditions