The effects of the modulation of NMDA receptors by homocysteine thiolactone and dizocilpine on cardiodynamics and oxidative stress in isolated rat heart.

In light of the limited data concerning the role of N-methyl-D-aspartate (NMDA) receptors in cardiac function, the aim of the present study was to determine the role of NMDA receptors in cardiac function, as well as the possible role played by the oxidative stress induced by the overstimulation of NMDA receptors in isolated rat heart. The hearts of male, Wistar albino rats (n = 24, 12 in each experimental group, BM 180-200 g) were retrogradely perfused at a constant perfusion pressure (70 cm H2O2), using the Langendorff technique, and cardiodynamic parameters were determined during the subsequent administration of DL-homocysteine thiolactone (DL-Hcy TLHC) alone, the combination of DL-Hcy TLHC and dizocilpine (MK-801), and MK-801 alone. In the second experimental group, the order of the administration of each of the substances was reversed. The oxidative stress biomarkers, including thiobarbituric acid reactive substances (TBARS), NO(2)(-), O(2)(-) and H2O2, were each determined spectrophotometrically. DL-Hcy TLHC and MK-801 depressed cardiac function. DL-Hcy TLHC decreased oxidative stress, a finding that contrasted with the results of the experiments in which MK-801 was administered first. The findings of this study were suggestive of the likely role played by NMDA receptors in the regulation of cardiac function and coronary circulation in isolated rat heart.

Population pharmacokinetics of 25-hydroxyvitamin D in healthy young adults.

OBJECTIVES: The aim of our study was to develop a population pharmacokinetic (PPK) model for 25-hydroxyvitamin D clearance in a healthy young adult population in Serbia. METHODS: Study sample consisted of 70 healthy young students of the Faculty of Medical Science, University of Kragujevac, Serbia, with a mean age and body mass index of 22.39 ± 1.82 years and 21.31 ± 2.69 kgm-2, respectively. Non-linear mixed-effect modeling (NONMEM) software was used for data analysis. A validation set of 16 participants was used to estimate the predictive performance of the pharmacokinetic model. RESULTS: In the base model (without covariates), we had parameter estimates of 0.01 L/h for apparent clearance, 0.25 L for apparent volume of distribution, while value of minimum objective function (MOF) was 383.468. The full regression model was established by estimating the effects of 12 covariates. Mean intake of vitamin D from foods (DD) and value of phosphate in serum (PHO) were covariates included in the final model, while others were excluded in this process. The estimated value in the final MOF model was 274.555. The final regression model formula was: clearance (CL) (L/h) = 0.0711 + 0.738 x DD + 0.618 x PHO. CONCLUSIONS: The PPK model obtained determined clearance of 25-hydroxyvitamin D in a healthy young adult population in Serbia. Mean intake of vitamin D from foods and serum phosphate level are the most important covariates that influence value of 25-hydroxyvitamin D clearance in healthy young adults.

Cytotoxic effect of Potentilla reptans L. rhizome and aerial part extracts.

Potentilla reptans L. belongs to the least studied of the plants from Rosaceae family, Potentilla genus. There are no data on cytotoxicity of P. reptans extracts, though traditionaly it was used as antiinflammatory and antiinfective. The aim of these studies was to investigate potential antitumor activity of aqueous extracts (rhizome and aerial parts) of P. reptans on 4T1 mouse breast cancer cell line. _Aqueous extracts of rhizome and aerial parts of P. reptans were tested for cytotoxicity by the MTT colorimetric assay on 4T1 cancer cell line in concentration range 100-800 microg/mL. Aqueous extracts of P. reptans rhizome and aerial parts show concentration dependent cytotoxic effect in the range of tested concentrations. ICE50 value of P. reptans rhizome extract was 280.51 +/- 1.16 microg/mL. IC50 value of P. reptans aerial parts extract was 310.79 +/- 1.22 microg/mL. The significant difference in cytotoxicity among tested concentrations was observed. Aqueous extracts of P. reptans rhizome and aerial parts demonstrated weak cytotoxic activity on 4T1 mouse breast cancer cell line, which is in correlation with current cytotoxicity data for aqueous herbal extracts. Rhizome extract of P. reptans has slightly higher antitumor activity than aerial parts extract. The results represent the first report on cytotoxicity for this plant and further research on human cell lines is indicated.

The use of dry Jerusalem artichoke as a functional nutrient in developing extruded food with low glycaemic index.

This study considers the use of dry Jerusalem artichoke (JA) as a functional nutrient in developing food products with enhanced nutritional characteristics and low glycaemic index (GI). Three different formulations based on buckwheat and JA were developed and processed using extrusion technology. Nutritional properties including the levels of total dietary fibre (TDF), protein, inulin, total carbohydrates and lipids were analysed. A clinical study was performed on ten healthy volunteers (aged between 21 and 56) to determine the level of GI and glycaemic load (GL). The results revealed that JA significantly (P<0.05) increased the levels of TDF and inulin whilst decreasing carbohydrates, lipids and proteins. The resulting products had a significant (P<0.05) effect on IAUC between reference food and extruded products, GI and GL. Samples containing 80% of Jerusalem artichoke were considered as a low GI food whilst samples containing 30% and 60% of Jerusalem artichoke as a medium GI food. A similar trend was seen in terms of GL.

Risk factors for severe dental anxiety among medical students.

BACKGROUND/AIM: Severe dental anxiety (SDA) is the most severe form of dental anxiety, thus the aim of this study was to determine the factors associated with SDA in students of health-related disciplines. METHODS: In this case-control study the cases were students with severe dental anxiety. The study was conducted at the Faculty of Medical Sciences, University of Kragujevac, Serbia. The participants were undergraduate students attending lectures during spring semester 2010/2011 (n = 1,812). A random sample of 800 students was assessed for the association between various risk factors and the severe dental anxiety. The main outcome measures were the data on demographics, dental anxiety, habits concerning oral hygiene, nutrition, general anxiety and (co)morbidity which were collected from the study participants by semi-structured questionnaire. RESULTS: Less frequent visits to the dentist (OR adjusted = 7.02 [2.65; 18.60]) and visiting the dentist only when there is a dental problem (OR adjusted = 8.08 [1.28; 50.93]) were associated with severe dental anxiety. The same was true for improper oral hygiene (OR adjusted = 4.25 [1.16; 15.60]). Factors as changing toothbrush more frequently (OR adjusted = 0.33 [0.14; 0.76]) and having chronic disease (OR adjusted = 0.01 [0.00; 0.09]) were inversely associated with severe dental anxiety. The level of education of students was not associated with severe dental anxiety. CONCLUSION: Inappropriate oral hygiene, less frequent changes of a toothbrush and less frequent visits to the dentist are important risk factors for severe dental anxiety.