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Béla Kovács, Előd Ernő Nagy, Norbert Nándor Chendrean, Blanka Székely-Szentmiklósi and Árpád Gyéresi

Abstract

As musculoskeletal diseases become an emerging healthcare problem worldwide, profound and comprehensive research has been focused on the biochemistry of bone metabolism in the past decades. Wnt signalling, one of the novel described pathways influencing bone metabolism from the early stages of tissue development, has been recently in the centre of attention. Several Wnt ligands are implied in bone forming pathways via canonical (β-catenin dependent) and non-canonical (β-catenin independent) signalling. Osteoporosis, a catabolic bone disease, has its pathologic background related, inter alia, to alterations in the Wnt signalling, thus key modulators of these pathways became one of the most promising targets in the treatment of osteoporosis. Antibodies inhibiting the activity of endogenous Wnt pathway inhibitors (sclerostin, dickkopf) are recently under clinical trials. The current article offers a brief review of the Wnt signalling pathways, its implication in bone metabolism and fate, and the therapeutic possibilities of osteoporosis through Wnt signalling.

Open access

Márton Horváth, Béla Solti, Imre Fatér, Tibor Juhász, László Haraszthy, Tamás Szitta, Zsuzsanna Ballók and Szilvia Pásztory-Kovács

Abstract

The diet composition of breeding Eastern Imperial Eagles (Aquila heliaca) was analysed in Hungary between 2005 and 2017, and compared with two previously published datasets from the periods of 1982–1991 and 1992–2004. Altogether the distribution of 8543 prey items of 126 different species and 29 other taxa were analysed within a 36-years period. We found that the previously abundant Common Hamster (Cricetus cricetus) became marginal (7.42%), while European Sousliks (Spermophilus citellus) practically disappeared (0.03%) from the diet of Imperial Eagles. Small game species, like the Common Pheasant (Phasianus colchicus) and the Brown Hare (Lepus europaeus) composed a remarkable part of the diet (11.22% and 28.11% respectively), which raised some conflicts with hunters regionally and probably also contributed to the high prevalence of persecution incidents against the eagles. In parallel with the loss of traditional prey species, corvids (13.10%), pigeons (8.90%), waterbirds (6.83%), other rodents (6.71%), Roe Deers (Capreolus capreolus) (5.59%), raptors and owls (4.88%) became regularly detected prey species. The temporal changes of the main prey categories were analysed between 1998 and 2017, when the ratio of Hamster and Pheasant showed significant decrease (-27.29% and -6.38%, respectively). The ratio of Brown Hare also showed slight decrease (-3.98%), but the change was not significant. On the other hand, the ratio of corvids, waterbirds and Roe Deers within the diet showed significant increase (+18.20%, +6.25% and +5.39%, respectively). The observed flexibility in the foraging behaviour of Imperial Eagles greatly facilitate conservation efforts, as they seems to be able to utilize the most abundant prey sources, i.e. they were not depending solely from the status of any single specific prey source. However, eagles could only shift and survive in those regions, where their traditional preys decreased, if alternative species were available for them.

Open access

Zoltán-István Szabó, Blanka Székely-Szentmiklósi, Boglárka Deák, István Székely-Szentmiklósi, Béla Kovács, Katalin Zöldi and Emese Sipos

Abstract

To evaluate the influence of different variables on tablet formulations containing enalapril maleate and indapamide as active substances, two separate experimental designs were employed: one for evaluating powder properties and the other for tablet characteristics. Because of the low active pharmaceutical ingredient content, it was hypothesized that both powder and tablet properties could be determined only by the characteristics of excipients. In order to test this assumption, both experimental designs were done with placebo mixtures. The optimized formulation was then evaluated both with and without APIs. Results indicated that filler and lubricant percentage, along with compression force, were the most important variables during the formulation study. The optimized formulation showed similar characteristics in both cases for all responses, except for angle of repose and friability where only minor differences were observed. The combination of the applied approaches (using placebo composition and fractional experimental design) proved to be efficient, cost effective and time saving.

Open access

Béla Kovács, Lajos Kristóf Kántor, Mircea Dumitru Croitoru, Éva Katalin Kelemen, Mona Obreja, Előd Ernő Nagy, Blanka Székely-Szentmiklósi and Árpád Gyéresi

Abstract

A reverse-phase HPLC (RP-HPLC) method was developed for strontium ranelate using a full factorial, screening experimental design. The analytical procedure was validated according to international guidelines for linearity, selectivity, sensitivity, accuracy and precision. A separate experimental design was used to demonstrate the robustness of the method. Strontium ranelate was eluted at 4.4 minutes and showed no interference with the excipients used in the formulation, at 321 nm. The method is linear in the range of 20–320 μg mL−1 (R2 = 0.99998). Recovery, tested in the range of 40–120 μg mL−1, was found to be 96.1–102.1 %. Intra-day and intermediate precision RSDs ranged from 1.0–1.4 and 1.2–1.4 %, resp. The limit of detection and limit of quantitation were 0.06 and 0.20 μg mL−1, resp. The proposed technique is fast, cost-effective, reliable and reproducible, and is proposed for the routine analysis of strontium ranelate.