Search Results

You are looking at 1 - 6 of 6 items for

  • Author or Editor: A. Nikolić x
Clear All Modify Search

Summary

Aripiprazole is a novel atypical antipsychotic drug used in the treatment of schizophrenia. The sensitive and reproducible ion pair RPLC method was developed and validated for determination of aripiprazole and its nine impurities, which are significantly different in polarity. The separation was performed on Phenomenex Luna® C18 column (5.0 μm particle size, 250 × 4.6 mm id) using a gradient mobile phase A (phosphate buffer pH 3.0) and mobile phase B (acetonitrile) at the working temperature of 25°C. The buffer was 1.11 g KH2PO4 with 1.2 g sodium pentanesulfonate/L of the solution, adjusted to pH 3.0 with orthophosphoric acid. The flow rate was 1.0 mL/min. The detection was carried out at 215 nm using a diode array detector. The developed method was validated according to the International Conference on Harmonization (ICH) guidelines for specificity, limit of detection, limit of quantification, linearity, precision and robustness. The proposed method is convenient and reliable for the purity control in both raw materials and dosage forms.

Full access

Tianeptine is a novel anti-depressant with an efficacy equivalent to that of classical anti-depressants. Additional beneficial effects include neuroprotection, anti-stress and anti-ulcer properties whose molecular mechanisms are still not completely understood but may involve changes in the anti-oxidant defence system. Herein, we have studied the effects of tianeptine on both contractile activity of isolated rat uteri and components of the endogenous anti-oxidative defence system. Tianeptine-induced dose-dependent inhibition of both spontaneous and Ca2+-induced contraction of uterine smooth muscle. The effect was more pronounced in the latter. Tianeptine treatment increased glutathioneperoxidase (GSH-Px) and catalase (CAT) activities in spontaneous and Ca2+-stimulated uteri. A significant decrease in glutathione-reductase (GR) activity in both spontaneous and Ca2+-induced uterine contractions after tianeptine treatment indicated a reduction in reduced glutathione and consequently a shift toward a more oxidised state in the treated uteri. In spontaneously contracting uteri, tianeptine caused a decrease in copper-zinc SOD (CuZnSOD) activity. Tianeptine’s anti-depressant effects may be accomplished by triggering a cascade of cellular adaptations including inhibition of smooth muscle contractility and an adequate anti-oxidative protection response.

Full access

Possible interactions between nitric oxide donors, reactive oxygen species and anti-oxidative defence enzymes led us to determine the activities of anti-oxidative defence enzymes in isolated uterine smooth muscle before and after spontaneous rhythmic activity ex vivo. For our experiments we used isolated uteri from female Wistar rats. Our results showed an increase in total superoxide dismutase (SOD) and Mn SOD activities in uterine smooth muscle after spontaneous contractions when compared with non-exercised uterine smooth muscle. The activity of catalase (CAT) and glutathione preoxidase (GSH-Px) were also increased. No statistically significant changes in the activities of glutathione reductase (GR) and CuZn SOD were found. It is known that an organism's anti-oxidative defence system (guarding against excessive reactive oxygen species generation) requires balanced increments in its individual anti-oxidative enzyme activities rather than increases in the activity of only some enzymes without increases in others. Thus, we may conclude that some adaptive responses are found in exercised uterine smooth muscle but are not complete. Therefore, our results indicate that changes in anti-oxidative enzyme activities may influence the results of the examination of substances ex vivo.

Full access
Imported parasitic infections in Serbia

Abstract

Background

Travel to the tropics is associated with a risk of parasitic infection, which is increasing in parallel with the rise in travel to these areas. We thus examined the prevalence and trend in the occurrence of parasitic infections in Serbian travelers.

Methods

A retrospective analysis of the medical records of all travelers returning from tropical and subtropical areas, who presented at the Institute for Infectious and Tropical Diseases in Belgrade between January 2001 and January 2008, was performed.

Results

Of a total of 2440 travelers, 169 (6.9%) were diagnosed with a parasitic infection, including malaria in 79, intestinal parasites in 84 (pathogenic species in 30 and non-pathogenic in 54), filariasis in four, and visceral leishmaniasis and fascioliasis in one patient each. Importantly, of the whole series only 583 (23.9%) were symptomatic, of which 19.4% were found to be infected with a parasite. The single pathogenic parasite occurring in asymptomatic patients was Giardia intestinalis.

Conclusions

Parasitic infection causing symptomatic disease among travelers returning from tropical areas to Serbia is not infrequent. In view of the expected increase in travel to the tropics, diagnostic protocols for tropical parasitic diseases should take these data into account.

Full access

Ketosis was diagnosed in a flock of Merino ewes that conceived from synchronised oestrus in the early autumn period. On day 140 of pregnancy the ewes were sampled for determination of βOH-butyrate (BHB), AST, glucose, non-esterified fatty acids (NEFA), total cholesterol (TCH), insulin, T4, T3, cortisol, IGF-1 and leptin. The results were evaluated according to the number of fetuses born some days later and the presence of hyperketonaemia (BHB: ≥ 1.60 mmol/l). In May, about 3 months after lambing, cyclic ovarian function was induced (Cronolone + eCG), and the ewes were inseminated artificially (AI) 48 h after the removal of gestagen-containing sponge. At the time of AI and 10 days later blood samples were collected again to check the plasma levels of the same constituents as previously (in samples taken at AI), and to monitor the ovarian response by assaying progesterone (in both samples). On day 140 of gestation significantly lower BHB levels were detected in dams with single (n = 41) than in those with twin (n = 57) pregnancies. Hyperketonaemia was found only in ewes bearing twins (n = 27). These animals had higher NEFA and cortisol, and lower TCH, insulin, IGF-1, leptin and T3 levels than their normoketonaemic twin-bearing flock-mates, and those with single pregnancy. The blood glucose concentrations varied within a wide range, and the means of groups did not exhibit any significant differences. The formerly hyperketonaemic individuals were characterised by lower leptin level 3 months after lambing, and they showed a poorer response to the cycle-induction procedure than the others. The non-responders had lower IGF-1 and leptin levels than those ovulated after this treatment. It was concluded that the subclinical form of ovine ketosis is characterised by complex endocrine alterations, reflecting an obvious form of negative energy balance. If attempts to induce cyclic ovarian function outside the breeding season are made soon after lambing, the ovarian response and fertility of these ewes may also be depressed.

Full access