257 research outputs found
The influence of diazinon and its metabolites on acetylcholinesterase, NA+/K+-ATPase and antioxidant enzymes in rat brain synaptosomes
The aim of this study was to investigate neurotoxic potential and oxidative stress responses of diazinon and its metabolites, diazoxon and 2-isopropyl-6-methyl-4-pyrimidinol using synaptosomes as a model system. Synaptosomes were isolated from the brain of Wistar albino rats and incubated at 37oC for 1 hour in the presence of selected concentrations of the investigated compounds. Acetylcholinesterase, Na+/K+-ATPase and antioxidant enzymes activities were determined by standard spectrophotometric methods. Diazinon induced concentration-dependent acetylcholinesterase and Na+/K+-ATPase inhibition, while the activity of catalase, superoxide dismutase and glutathione peroxidase was not significantly affected. Increasing concentrations of diazoxon, oxo analog of diazinon, caused almost complete acetylcholinesterase and Na+/K+-ATPase inhibition, and activated antioxidant enzymes: catalase (up to 25%), superoxide dismutase (up to 55%) and glutathione peroxidase (up to 30%). Unlike diazoxon, diazinon hydrolysis product, 2-isopropyl-6-methyl-4-pyrimidinol did not remarkably change the activities of the investigated enzymes, except superoxide dismutase that was stimulated up to 25%. The obtained results suggest that neurotoxic and prooxidative potential of diazinon, thioorganophoshate used as a commercial insecticide preparation, significantly reinforces mostly due to its transformation to diazoxon in the metabolic pathways.Third International Conferenceon Radiation and Applications in Various Fields of Research, RAD 2015, June8-12, 2015, Budva, Montenegr
Detailed characterization of the Ti-O based thin films obtained by cathodic arc evaporation
Physicochemical properties of thin films on the base of titanium oxides, obtained by a cathodic arc evaporation on the surface of glass substrate are analysed in details. The analysis of these films was made by using XRD, FTIR, SEM, XPS analysis and ellipsometry. On the basis of these analyses, particularly analysis obtained by XPS, the oxidative state Ti and corresponding phases are determined through various film layers from the surface to the substrate. The depth of the various levels and their extinction coefficients and refractory indexes are estimated by ellipsometry
Partial replacement of soybean meal with pumpkin seed cake in lamb diets: Effects on carcass traits, haemato-chemical parameters and fatty acids in meat
The composition of lamb diets has an effect on production traits and meat quality, especially fatty acid proportions. Recently, in organic farming, soybean meal has frequently been replaced with feedstuffs that are rich in protein. The aim of the present study was to determine the effects of partial replacement of soybean meal with pumpkin seed cake on carcass traits, biochemical parameters and fatty acids of lamb meat produced in organic farming. The research was carried out on 70-day-old lambs of the Merinolandschaf breed. Thirty-six lambs were grouped by gender, and allotted to three treatment groups, which were given one of the three diets: control diet with no pumpkin seed cake; a diet in which 10% of soybean meal was replaced with 10% pumpkin seed cake; and a diet in which 15% of soybean meal was replaced with 15% pumpkin seed cake. The experimental feeding period was 30 days. Hay and water were provided ad libitum. Differential blood tests and haematological parameters were determined, and the concentrations of minerals and biochemical parameters, and enzyme activity were ascertained in blood serum. Carcass traits and lamb meat colour did not differ among dietary treatments. Significant differences were observed in the concentrations of some biochemical parameters, which indicated good energy and protein balance, and changes in fat metabolism that did not impair antioxidant status. Compared with the control, the concentration of linoleic acid (C18:2 n-6) was higher in diets containing 10% and 15% of pumpkin seed cake replacements. The results indicated that partial replacement of soybean meal with 10% or 15% of pumpkin seed cake could be implemented in lamb feeding in organic farming without major changes in carcass traits, haemato-chemical parameters and the fatty acid profile in meat.Keywords: Blood parameters, meat quality, Merinolandschaf lambs, organic farmin
Anti-toxocara antibodies in patients with suspected visceral larva migrans and evaluation of environmental risk of human infection in Belgrade, Serbia
Toxocariasis is a frequent zoonotic parasitosis in Serbia. The aim of the study was to examine anti-Toxocara IgG antibodies in serum and cerebrospinal fluid (CSF) in patients with suspected visceral larva migrans (VLM) in Belgrade, and to estimate the prevalence of T. canis eggs in dog fecal deposits collected in green public areas. A total of 145 patients were examined by ELISA. In 26.39% (38/144) of serum samples, T canis IgG were detected, and in 6 CSF samples, 2 were positive for antibodies. Seropositivity was detected in 26.1% (34/130) adults and 33.3% (5/15) children. A total number of 155 fresh dog feces were collected in five public parks in Belgrade where T canis eggs were identified with a prevalence of 33.55% (52/155). Based on the high prevalence of parasite eggs, we estimated a high risk of human infection by T canis eggs in public green areas in Belgrade
Cytotoxicity investigation of a new hydroxyapatite scaffold with improved structural design
Introduction Biodegradable porous scaffolds are found to be very promising bone substitutes, acting as a temporary physical support to guide new tissue regeneration, until the entire scaffold is totally degraded and replaced by the new tissue. Objective The aim of this study was to investigate cytotoxicity of a synthesized calcium hydroxyapatite-based scaffold, named ALBO-OS, with high porosity and optimal topology. Methods The ALBO-OS scaffold was synthesized by the method of polymer foam template. The analysis of pore geometry and scaffold wallstopography was made by scanning electron microscope (SEM). The biological investigations assumed the examinations of ALBO-OS cytotoxicity to mouse L929 fibroblasts, using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromidefor (MU) and lactate dehydrogenase (LDH) tests and inverse phase microscopy. Results The SEM analysis showed high porosity with fair pore distribution and interesting morphology from the biological standpoint. The biological investigations showed that the material is not cytotoxic to L929 cells. Comparison of ALBO-OS with Bio-Oss, as the global gold standard as a bone substitute, showed similar results in MTT test, while LDH test showed significantly higher rate of cell multiplication with ALBO-OS. Conclusion The scaffold design from the aspect of pore size, distribution, and topology seems to be very convenient for cell adhesion and occupation, which makes it a promising material as a bone substitute. The results of biological assays proved that ALBO-OS is not cytotoxic for L929 fibroblasts. In comparison with Bio-Oss, similar or even better results were obtained
Inhibition of ache by malathion and some structuraly similar compounds
Inhibition of bovine serum acetylcholinesterase by in vitro exposure to malathion, malaoxon, isomalathion and diethyl maleate was investigated to elucidate the mechanism of the enzyme interaction with structurally similar organophosphorus compounds. IC50 (half maximum inhibitory concentrations) were determined by Hill analysis of experimentally obtained inhibition curves. The values (2.87 ± 0.24)x10-6 M, (2.65±0.61)x10-6M, (3.01±0.36)x10-4 M and (5.69 ±0.7)x10-2 M were obtained for malaoxon, isomalathion, malathion and their hydrolysis product diethyl maleate, respectively. The relationship between the structure of the compounds and their potency to inhibit the enzyme activity was discussed.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200
Endometrial immunocompetent cells in proliferative and secretory phase of normal menstrual cycle
Background: Menstruation was presented as a result of inflammatory process. The total and relative numbers of the endometrial immunocompetitive cells vary during the different phases of the menstrual cycle. The aim of this morphological study is to make a contribution to understanding different distribution of leukocyte types during proliferative and secretory phase of normal menstrual cycle.
Materials and methods: The study included 40 women (20 in proliferative and 20 in secretory phase of the menstrual cycle). Exploratory curettage performed as preoperative preparation due to uterine myomas. Immunophenotyping was performed by immunoalkaline phosphatase (APAAP) using monoclonal antibodies: CD15, CD20, CD30, CD45RO, CD56, CD57 and CD68. The results were statistically analysed using SPSS 20.0 software.
Results: Natural killer (NK) cells are dominant during secretory, and CD45RO T lymphocytes are dominant during proliferative phase of the menstrual cycle. During the secretory phase of menstrual cycle, leukocytes make 30% of total endometrial cells. NK cells (CD56+ bright subpopulation), activated T lymphocytes, macrophages and B lymphocytes significantly increase in their number during the secretory phase of menstrual cycle.
Conclusions: Significant changes in endometrial leukocyte populations during proliferative and secretory phase of the menstrual cycle are emphasized. Changes in dominance of different leukocyte subpopulations are determined by hormonal and microenvironmental changes in modulatory factors that have not yet been fully explained
Effect of polyoxometalates on synaptic plasma membrane structure
12-tungstosilicic acid (SiW12) and decavanadate (V10) are polyoxometalate compounds (POMs) exhibiting biological activity. In vitro studies of the influence SiW12 and V10 on synaptic plasma membrane (SPM) acetylcholinesterase (AChE) and Na,K-ATPase, respectively, showed that these POMs inhibit the enzyme activities in submicromolar concentrations. As Na,K-ATPase and AChE are membrane associated enzymes, the inhibition of their activities can result from the membrane changes induced by the inhibitor binding. Thus, the effect of SiW12 and V10 on the membrane structure was investigated by using Atomic Force Microscopy (AFM) technique. The obtained results demonstrated that the calculated average roughness values for SiW12 and V10 treated SPM were significantly higher (about 6 and 1.5 times, respectively), compared to untreated SPM preparation. The obtained changes indicate that both investigated POMs bind to the plasma membranes, and consequently their approved strong inhibitory potencies toward the membrane bound enzymes might be assigned to the induced membrane modifications.14th international conference on fundamental and applied aspects of physical chemistry; 24-28 September 2018, Belgrade, Serbia
Design of Li phosphorous doped bronzes obtained by using spray pyrolysis
The ultrasonic spray pyrolysis technique has been, during last three decades, one of the major techniques of synthesis a wide variety of materials. One of the most important among the ionic conductors is lithium phosphorous doped tungsten bronze. The main goal of this investigation is producing full or hallows spheres of these bronzes of very narrow distribution. The mean size and size distribution specter of all materials were determined by the SEM analysis. The results were compared with the values obtained from the theoretical model. The assembled results indicate the possibility of a rigorous particle structure designing of all obtained powders.17th International Vacuum Congress/13th International Conference on Surface Science/International Conference on Nanoscience and Technology, Jul 02-06, 2007, Stockholm, Swede
Modelling and experimental investigations of thin filmsof Mg phosphorus-doped tungsten bronzes obtainedby ultrasonic spray pyrolysis
In this study, the synthesis of thin films of Mg phosphorus doped tungsten bronzes (MgPTB; MgHPW(12)O(40).29H(2)O) by the self-assembly of nano-structured particles of MgPTB obtained using the ultrasonic spray pyrolysis method was investigated. As the precursor, MgPTB, prepared by the ionic exchange method, was used. Nano-structured particles of MgPTB were obtained using the ultrasonic spray pyrolysis method. The nano-structure of the particles used as the building blocks in the MgPTB thin film were investigated experimentally and theoretically, applying the model given in this article. The obtained data for the mean particle size and their size distribution show a high degree of agreement. These previously tailored particles used for the preparation of thin films during the next synthesis step, by their self-assembly over slow deposition on a silica glass substrate, show how it is possible to create thin MgPTB films under advance projected conditions of the applied physical fields with a fully determined nanostructure of their building block particles, with a relatively small roughness and unique physical properties
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