Horváth Emőke, Finna Csilla, Demian Smaranda and Nagy Előd-Ernő
Béla Kovács, Előd Ernő Nagy, Norbert Nándor Chendrean, Blanka Székely-Szentmiklósi and Árpád Gyéresi
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.
Béla Kovács, Lajos Kristóf Kántor, Mircea Dumitru Croitoru, Éva Katalin Kelemen, Mona Obreja, Előd Ernő Nagy, Blanka Székely-Szentmiklósi and Árpád Gyéresi
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.