Zagorka Lozanov-Crvenkovic

Partial Least-Squares Study of the Effects of Organic Modifier and Physicochemical Properties on the Retention of Some Thiazoles

Reversed-phase (RP) HPTLC with aqueous ammonia-organic modifier (acetonitrile, dioxane, acetone) mobile phases has been used to study the effect on retention of the chromatographic system and the physicochemical properties of twelve 2,4-dioxotetrahydro-1,3-thiazoles. A multivariate approach to the retention behavior of these 1,3-thiazoles with three quite different organic solvents was used to explain the interactions between the analytes and the mobile phases. Principal-component analysis (PCA) and partial least-squares (PLS) regression were used to determine the molecular properties with the greatest effect on retention for each modifier. Good correlation was obtained between experimental and calculated retention data.

Early pregnancy angiogenic proteins levels and pregnancy related hypertensive disorders

Abstract Introduction: Normal placental vascular development depends on multiple interactions of many regulatory molecules including pro and antiangiogenic proteins. It is considered that these vascular modulators might be one of the factors responsible for development hypertensive disorders in pregnancy. Objective: To evaluate and compare the early pregnancy (11–14 week of gestation) serum level of angiogenic proteins sFlt1, VEGF i PIGF between different types of pregnancy related hypertensive disorders. Materials and methods: The study included 177 pregnant women between 11 and 14 weeks of gestation, divided into four study subgroups (preeclampsia group-41, gestational hypertension group-31, chronic hypertension group-32 and miscarriage group-19) and control group-54. Blood samples (serum) were taken for measuring sFlt1, VEGF i PIGF by a quantitative ELISA technique and measuring other biochemical and hematological parameters. Results: Significantly higher levels of sFlt1 were in the subgroups with preeclampsia and miscarriages, significantly lower level of VEGF in the all study subgroups and lover level of PIGF were in miscarriage group. In the groups with chronic and gestational hypertension there were higher level of sFlt1 and lover level of VEGF than in the control group, but the differences did not reach statistical significance. Conclusion: Early pregnancy imbalance between antiangiogenic protein sFlt1 and proangiogenic molecules VEGF and PIGF could have impact on pathophysiology of placental disorders which leads to development of pregnancy related hypertensive disorders.

On some classes of generalized random linear functionals

Abstract Representation theorems for some new classes of random linear functionals and an application of these results in solving stochastic evolution equations are given.

Clinical significance of determining plasma homocysteine: case-control study on arterial and venous thrombotic patients.

Aim To determine the differences in plasma homocysteine levels between three MTHFR 677 genotype subgroups in patients with thrombosis and in controls, as well as between patients with thrombosis and controls with the same MTHFR 677 genotype. Methods This case-control study was conducted in Clinical Center of Vojvodina, Novi Sad, from June to December 2011. We included 65 patients with either arterial or venous thrombosis (mean age, 40.97 ± 11.38 years) and 65 controls with no history or clinical evidence of any thrombotic event (mean age, 41.23 ± 11.12 years). Patients and controls were age- and sex-matched. Results In comparison with controls, thrombotic patients had significantly higher homocysteine levels (12.81 ± 4.94 µmol/L vs 9.82 ± 3.68 µmol/L; P < 0.001) and significantly higher incidence of hyperhomocysteinemia (55% vs 22%; P < 0.001; odds ratio [OR] = 4.521). There were no significant differences in homocysteine levels between homozygous carriers, heterozygous carriers, and non-carriers of the MTHFR 677 mutation in either thrombotic patients (12.97 ± 5.40 µmol/L vs 12.55 ± 5.71 µmol/L vs 13.27 ± 1.71 µmol/L; P = 0.100) or controls (10.07 ± 2.50 µmol/L vs 10.25 ± 4.84 µmol/L vs 9.20 ± 2.44 µmol/L; P = 0.651). However, in comparison with controls, homozygous carriers in thrombotic patient group did not have significantly higher levels of homocysteine (12.97 ± 5.40 µmol/L vs 10.07 ± 2.50 µmol/L; P = 0.072), but heterozygous carriers (12.55 ± 5.71 µmol/L vs 10.25 ± 4.84 µmol/L; P = 0.020) and non-carriers (13.27 ± 1.71 µmol/L vs 9.20 ± 2.44 µmol/L; P < 0.001) did. There was no significant difference in homocysteine levels between patients with arterial and venous thrombosis (12.76 ± 3.60 µmol/L vs 12.86 ± 5.51 µmol/L; P = 0.990) and between patients with one thrombotic event and those with recurrent thrombotic events (12.14 ± 3.20 µmol/L vs 15.25 ± 8.51 µmol/L; P = 0.254). Conclusion Plasma homocysteine levels have a greater clinical significance in the prevention of thrombosis and managing its complications than MTHFR 677 genotyping.

SUBSTITUENT EFFECTS ON CHROMATOGRAPHIC RETENTION DATA OF 5-ARYLIDENE-2,4-THIAZOLIDINEDIONES IN QSAR METHODOLOGY

Quantitative structure-retention relationship (QSRR) study of retention data of thirteen 5-arylidene-2,4-thiazolidinediones obtained by reversed phase HPTLC. The effect of substituents attached to aryliden ring on the properties of TZD molecule, whose retention is closely correlated to the inhibitory activity, was investigated. PCA was used to show similarities/dissimilarities among the compounds. Stepwise regression models were calculated for each mobile phase modifier used. The obtained models were characterized by good fit and predictive abilities. The descriptors included in the models are connected with both lipophilic and donor/acceptor interactions.

Preeclampsia and level of oxidative stress in the first trimester of pregnancy

Background/Aim. Introduction: Preeclampsia (PE) is a multisistemic syndrome that complicates 5-8% of all pregnancies. The aim of this study was to evaluate the biochemical parameters of oxidative stress in the first trimester of pregnancy in patients with preeclampsia, with the purpose of comparing the level of oxidative stress with normal pregnancy. Materials and methods. The study was conducted as a prospective study. The study included total of 107 pregnant women divided into two groups. In the study group (n=33) there were women who developed preeclampsia in the current pregnancy. The control group (n=74) were healthy pregnant women. Blood samples were taken between 11. and 14. weeks of gestation, and the values of Superoxide dismutase (SOD), Glutathione peroxidase (GSH-Px) and Total antioxidant status (TAS) were determined in serum by enzymatic colorimetric methods. Results. The values of SOD and GHS-Px were statistically higher in the study group, while the values of TAS were statistically higher in the control group. The level of TAS correlated with GSH-Px and SOD correlated with TAS, but there is no statistical significant correlation between GSH-Px and SOD in the study group. Conclusion. The results of this study suggest a higher level of oxidative stress in the first trimester of pregnancy with preeclampsia, which may indicate that the initiation and development of pathophysiological processes underlying preeclampsia start much earlier than the clinical syndrome exhibit. [Projekat Ministarstva nauke Republike Srbije, br. 174019]

General fuzzy integral as a base for estimation of fuzzy quantities

Abstract Estimation of fuzzy quantities is a topic that often appears in decision making. Some of the well-known approaches are based on the integration done with respect to the probability measure and, later on, on the possibility measure and the necessity measure. The approach considered here is focused on a fuzzy measure in general as a base of integration.

On Sugeno integral based mean value for fuzzy quantities

Evaluation of fuzzy quantities is a contemporary issue that often appears in the process of modeling uncertainty. Some of the well-known approaches are based on the integration done with respect to the probability measure, while the approach presented here considers a fuzzy measure as a base of integration. The integral in question is the Sugeno integral and it is used for construction of the Sugeno based mean value for some specific fuzzy quantities.

Water quality changes after Kraljevo earthquake in 2010

AbstractMany studies have examined earthquake’s impacts on hydrological changes such as drying up and flooding of (water) wells, fluctuation of groundwater levels, and changes in water quality. This paper aims to present water quality changes in the aftermath of a November 2010 earthquake in Kraljevo. Water quality changes followed hydrological, geological, and geomorphological changes. The water parameter concentrations were measured before the earthquake in 2010 and after that in 2010 and 2011, as well as 2009 and 2012. The data from two hydrological stations were used: Kraljevo Zapadna Morava and Kraljevo Ibar. The Canadian Water Quality Index was applied for the calculation of water quality. This method defines the overall water quality and the specific quality of water used for drinking, aquatic habitats, recreation, irrigation, and livestock. A significant decline in the quality of water used for aquatic habitat and a less significant one in the overall quality and the quality of water used for irrigation was recorded in the hydrological station Zapadna Morava. Increased heavy metal concentrations were detected, which caused water quality impairment. A minor decline in the overall water quality and the quality of water used for aquatic habitats was recorded in the hydrological station Kraljevo Ibar.