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Open access

Pavle Premović, Budimir Ilić and Dragan Đorđević

A new method for determining the concentration of vanadyl ions in clays

A novel and simple method for quantitatively determining the concentration of vanadyl ions in clays using electron spin resonance data has been developed. Several vanadyl standards with concentrations between 200-1000 ppm were prepared in a mixture of glycerol and kaolinite (KGa-2). The anisotropic electron spin resonance (ESR) spectra were recorded at room temperature, and the specific intensity of the line (attributed to nuclear spin m = -5/2||) was determined. For vanadyl concentrations between 50 ppm and 200 ppm, the standards must be prepared by mixing kaolinite with known vanadyl content (FBT2A-03) and kaolinite (GB1) containing no vanadyl. The method is applicable without modification to other clays and clay-rich sediments containing vanadyl ions. The whole procedure is very suitable for routine work.

Open access

Aleksandar Joksimović, Daniel Stanković, Dragan Ilić, Ivana Joksimović and Milorad Jerkan

Hematological Profile of Serbian Youth National Soccer Teams

Soccer is one of the most widely played and complex sports in the world, where players need technical, tactical, and physical skills to succeed. Technical and tactical skills in soccer are highly dependent on the player's physical capacity. The selection, development and professional guidance of young players is a priority for many top soccer clubs in order to maintain their sporting and financial status. The aim of the present study was to determine hematological profile of youth national soccer teams and to compare the values of fifteen hematological parameters between 3 Serbian youth national teams (under 14, 15 and 16 years old), as well as between soccer players and nonathletes. 80 young soccer players and 30 non-athletes participated in the study. 15 hematologic parameters (WBC, RBC, HGB, HCT, PLT, MCV, MCH, MCHC, PDW, LYM%, MON%, GRAN%, LYM, MON, GRAN) were measured. In order to determine the significance of differences between the groups on a multivariate level a multivariate analysis of variance (MANOVA) was administered, and to test the differences between the groups on an univariate level a univariate analysis of variance (ANOVA) was applied. It was concluded that there is no significant difference in all the variables (WBC, Ly, Mo, Gr, PLT, HGB, HCT, etc), except RBC, probably due to age, androgen affection on erythropoesis, field positoning and diet. From a practical point of view, the clinician has to take into account not only age, but also training status of individuals when evaluating their blood tests.

Open access

Ivan Matović, Dragan V. Ilić, Renata Petrović and Dejan Ostojić

Summary

Introduction Prognosis of endodontically treated tooth is directly correlated to the quality of apical obturation. Modern concept of endodontics in particular way points out the quality of apical filling. The aim of this study was to assess the quality of root canal obturation with MTA apical plug using the method of gas (argon) penetration.

Material and Methods Sixty-six freshly extracted single rooted (single canal) teeth were divided into the two experimental (30 teeth) and one control group (6). All canals were instrumented using hand and rotary files in step-back technique and copious irrigation of 1%NaOCl. In the first experimental group teeth were obturated using different sealers: Gutta Flow (Roeko), AH Plus (DeTrey), Acroseal (Septodont) and mono gutta-percha cone (10 canals each). In the second experimental group obturation involved 3 mm of MTA-Angelus apical plug while the remaining canal space was filled with the same three sealers as in the first group. The rate of gas permeability by Leak detector-Edwards LD 416 was measured in all teeth.

Results The best seal was found in teeth obturated with Gutta Flow and MTA plug with average diffusion rate of 264.4 sec while the worst quality of obturation was found with Acroseal (178.5 sec-the highest gas permeability). All samples with MTA plug exhibited significantly lower leakage than the samples filled without MTA apical plug.

Conclusion Root canals filled with MTA apical plug exhibited statistically significant lower gas permeability in comparison to the ones filled with sealer and guttapercha cones only.

Open access

Jovana Cvetković, Dragan Đ Đorđević, Milan Šljivić and Marina Deljanin Ilić

Summary

Herein we present a 25-year-old female patient with tetralogy of Fallot (TOF). This congenital heart defect is not very common, but it is the most common one among cyanotic heart defects. Treatment of the patients with TF is surgical, with palliative or curative (corrective) intent. Our patient underwent palliative surgery, definitive correction, and another surgery for pulmonary valve insufficiency. During cardiovascular rehabilitation, the patient was rhythmically stable, with excellent tolerance of physical exertion. Bearing in mind that this was a young female person who previously had had two spontaneous abortions, pregnancy was not absolutely contraindicated, although spontaneous abortion and pregnancy complications were more common in these patients.

Open access

Milica Stojić, Natalija Fratrić, Marijana Kovačić, Vesna Ilić, Dragan Gvozdić, Olivera Savić and Radojica Đoković

Abstract

Failure of passive transfer (FPT) of immunoglobulins (IgG) is associated with increased morbidity and mortality of calves. In this study we evaluated the digital Brix refractometer usefulness for the assessment of FPT. A number of 16 colostrum samples from the first milking (2-3h post-partum) of Holstein-Friesian dairy heifers and 29 blood sera of 3-6 days old calves were analyzed with a digital Brix refractometer. Total proteins were determined by the biuret reaction. Colostral IgG were determined by radial immunodiffusion (RID), and colostral whey and blood serum γ globulin (composed almost entirely of IgG) were determined by agarose protein gel electrophoresis (APE) and densitometry. Colostral % Brix score was 25.5±3.4%. Concentrations of colostrum IgG and colostral whey γ globulin were 130±33 g/L and 100±24 g/L respectively. The concentration of total proteins in colostral whey was 134±30 g/L. The correlations between Brix values and the concentrations of IgG determined with RID and the concentrations of γ globulin determined with APE were positive and highly significant (P<0.001 and P<0.01). The concentration of serum proteins of new-born calves was 57.75±11.8 g/L, the concentration of γ globulin was 14.4±7.8 g/L, and the Brix score was 8.6±1.0%. FPT (serum γ globulin<10 g/L) was detected in 34.5% (10/29) calves. Brix score correlated with the concentration of blood serum γ globulins in all examined calves. The results have confirmed that digital Brix refractometry allows the producers to use this technique in order to estimate colostral and calf serum IgG, thereby monitoring both colostrum quality and success of passive transfer.

Open access

Jelena Bjelica, Ivan B. Jovanović, Vesna Ilić, Olivera Valčić, Danijela Kirovski, Dragan Gvozdić and Svetlana Milanović

Abstract

Both selenium, as an effector and regulator of antioxidative enzymes activity, and thyroid hormones are potent immunomodulators. Besides, selenium incorporated into iodothyronine deiodinases is involved in the thyroid function and thus indirectly regulates the immune response. Studies of the mutual influence of selenium and thyroid hormones on the immune response are scarce, hence we analyzed the effects of an iodothyronine deiodinases blocker, propylthiouracil (PTU), and selenium deficiency on the function of peritoneal macrophages, and titer of naturally occurring anti-sheep red blood cells (SRBC) IgM antibodies in juvenile rats. The experiment was carried out on 64 Wistar male rats allotted to 4 groups: controlselenium adequate PTU- group; selenium adequate, PTU+ group; selenium defi cient, PTU- group; and selenium defi cient, PTU+. The selenium adequate and selenium defi cient groups were fed a diet containing 0.334 and 0.031 mg Se/kg, respectively. PTU+ groups received PTU (150 mg/L) in drinking water. After 3 weeks, thyroxine (T4), triiodothyronine (T3), and thyroid stimulating hormone (TSH) were determined. The animals having “intermediate” concentrations of T3 (1.56-1.69 nmol/L) and T4 (41-50 nmol/L) were excluded from further analysis. Thus, PTU+ groups included hypothyroid animals (T3≤1.55 nmol/L; T4≤40 nmol/L), while PTU- groups included euthyroid rats (T3≥1.70 nmol/L; T4≥50 nmol/L). Both groups of selenium deficient rats had, when compared to the control group, a significantly lower activity of glutathione peroxidase GPx1 and GPx3. Neither selenium deficiency nor PTU influenced the adherence of peritoneal macrophages. Selenium deficiency significantly decreased the peroxide synthesis in macrophages and significantly increased the titer of anti-SRBC IgM. Hypotyroidism alone or in combination with selenium deficiency had no influence on these parameters.

Open access

Dragan V Ilić, Kosovka Obradović-Đuričić, Vesna Medic, Srđan Poštić, Stanislava Z Gorjanović, Ferenc Pastor and Katarina Radović

Summary

Background: Free radicals (FR) occur in oral cavity where lot of food was transferred to through entire life under specific saliva conditions. Many enzymes, microorganism, alcohol beverages, nicotine and other harmful or indifferent substances when in contact to oral tissues might provoke oxidation process under specific condition creating FRʼs. The similar role might have various dental materials.

Aim: Of the study was to record the level of antioxidant (AO) activity of several permanent (P) luting cements alone or combined with quercetin AO substance.

Materials/Methods: P cements were Zn-phosphate, Zn-polycarboxilate, GIC and composite resin cement. They were prepared as original prescription and their variant by 1%weight addition of quercetin. AO activity of cements was measured by HPMC test evaluated by Student t test.

Results: There were statistically significant differences among Zn-phosphate, Zn-polycarboxilate and resin dental cements (p ˃ 0,05). GIC displayed significantly higher AO values (p < 0,01) versus other three cements. There were no difference in AO capacity between sample of original P cements and their corresponding quercetin variants (p ˃ 0,05).

Conclusions: Conventional GIC displayed the most powerful AO activity among P luting cements. Addition of 1% antioxidant quercetin did not improve AO capacity of investigated cements.

Open access

Marija Stojanović, Ljiljana Šćepanović, Olivera Bosnić, Dušan Mitrović, Olga Jozanov-Stankov, Vuk Šćepanović, Radomir Šćepanović, Teja Stojanović, Slobodan Ilić and Dragan Djurić

Abstract

Oxidative stress appears to play a role in the pathogenesis of several inflammatory gastrointestinal diseases. Increased homocysteine levels may play a role in the pathogenesis of Chron’s disease and ulcerative colitis. The aim of this study was to examine the influence of homocysteine on the antioxidant status of rat intestine and liver. The levels of thiobarbituric acid reactive substances (TBARS), activity of catalase (CAT) and total antioxidant status (TAS) were investigated in the isolated gut and liver of young male rats in the control group (8 rats) and after 3-hоur incubation in high doses of D, L-homocysteine thionolactone (Hcy) (10 μmol/L) (8 rats). Samples of duodenum, ileum, colon and liver were homogenized in sodium phosphate buffer (1:10). Homogenates were centrifuged at 10000 for 10 min at 4° C and the supernatant was taken for biochemical assays. Our results showed that high D, L-homocysteine thionolactone concentration reduced enzymatic catalase activity in homogenates of the isolated segments of duodenum (27.04%) p<0.01; ileum (37.27%), colon (34.17%) and liver (67.46%) p<0.001. Exposition to high D,L-homocysteine thiolactone concentration significantly increased TBARS levels in the duodenum (106.05%), ileum (47.24%), colon (112.75%) and liver (32.07%) (p<0.01). Homocysteine also modifi ed the total antioxidant status of homogenates from the duodenum, ileum, colon and liver, increasing by 20.68% (duodenum), 24.74% (ileum), 14.88% (colon) and 19.35% (liver) (p<0.001). Homocysteine induced a consistent oxidative stress in rat’s intestine and liver (reduced activity of catalase and increased level of TBARS), but the elevated activity of TAS in our experiments could be explained as an adaptive response to the generated free radicals which indicates the failure of the total antioxidant defense mechanism to protect the tissues from damage caused by homocysteine.

Open access

Marija Stojanović, Ljiljana Šćepanović, Dušan Mitrović, Vuk Šćepanović, Radomir Šćepanović, Marko Djuric, Slobodan Ilić, Teja Šćepanović and Dragan Djuric

Abstract

Recent studies have confirmed that hyperhomocysteinemia is associated with gastrointestinal diseases; however, the direct effect of homocysteine on gastrointestinal reactivity still remains unknown. The aim of this study was to demonstrate how homocysteine may affect nitric oxide mediated duodenal relaxation and whether cholinergic receptors and K+ channels take part in stimulating motility, as well as to explore whether oxidative stress is associated with homocysteine-mediated effects. Experiments were carried out on male rats, body mass 250-300 g. Two groups of animals were treated by i.p. application of saline and D,L-Hcy (0.6 μmol/g bm). After 2h of incubation, the duodenal segments were prepared for biochemical analysis and contractile response measurements in an organ bath with Tyrode’s solution. Effects of TEA (10 mmol/L) and L-NAME (30 μmol/L) on duodenal contractility in the presence of D,L-Hcy (0.6 μmol/g bm) were investigated. Elevated homocysteine levels seem to be of crucial importance for the deterioration of contractility through nitric oxide mediated relaxation, and, in part, by activation of K+ channels. Hcy showed direct promuscarinic effects, since 30 min pretreatment of rat duodenum significantly enhanced the contractile effect of increasing concentrations of ACh (10−9-10−2 mol/L). Catalase activity, superoxide dismutase, glutathione peroxidase and the total antioxidant system were reduced while the thiobarbituric acid-reactive substances level was elevated. Our data showed a consistent profile of gastrointestinal injury elicited by sulfur-containing amino acid-homocysteine. This could contribute to explain, at least in part, the mechanisms involved in human gastrointestinal diseases associated to hyperhomocysteinemia.