Statin-induced calcific Achilles tendinopathy in rats: comparison of biomechanical and histopathological effects of simvastatin, atorvastatin and rosuvastatin

Accumulating clinical evidence indicates the risk of tendinopathy and spontaneous and/or simultaneous tendon ruptures associated with statin use. This experimental study was designed to evaluate and compare the biomechanical and histopathological effects of the three most commonly prescribed statins (simvastatin, atorvastatin and rosuvastatin) on the Achilles tendon in rats

Serum selenium levels of children living in Adana, Turkey

This study describes the measurement of selenium concentrations in serum from children aged 7-8 and 11-12 years who lived in Adana, Turkey. Serum selenium was measured by electrothermal atomization atomic absorption spectrometry (ETAAS) using Ni as the chemical modifier. Calibration was achieved by standard additions. A program for analytical quality assurance was undertaken. The serum selenium concentrations of 100 children aged 7-8 and 11-12 years were, mean ± SD (range), 0.73 ± 0.11 µmol/l (0.56-0.89 µmol/l), and 0.92 ± 0.10 µmol/l (0.70-1.13 µmol/l), respectively. Distribution of serum selenium levels according to sex did not differ significantly. The size of our study group is sufficiently large to describe the selenium status of children in Adana, Turkey. The results obtained indicate that no active intervention to regulate selenium status is necessary

Oral toxicity of pefloxacin, norfloxacin, ofloxacin and ciprofloxacin: comparison of biomechanical and histopathological effects on Achilles tendon in rats

Four fluoroquinolones (pefloxacin, norfloxacin, ofloxacin and ciprofloxacin) were compared according to their biomechanical and histopathological effects on rat Achilles tendon. Wistar rats were divided into one untreated control and four treatment groups in parallel. Pefloxacin mesylate dihydrate (40 mg/kg), norfloxacin (40 mg/kg), ofloxacin (20 mg/kg) and ciprofloxacin (50 mg/kg) were administered by gavage twice daily for three consecutive weeks. 6 weeks after treatment, the test animals were euthanised and Achilles tendon specimens were collected. A computer monitored tensile testing machine was utilised for biomechanical testing. The mean elastic modulus of the control group was significantly higher than that of the norfloxacin and pefloxacin groups (p < 0.05 and p < 0.01, respectively). The mean yield force (YF) of the control group was significantly higher than those of ciprofloxacin, norfloxacin and pefloxacin groups (p < 0.001, p < 0.05 and p < 0.01, respectively). The mean ultimate tensile force (UTF) of the control group was significantly higher than of the ciprofloxacin, norfloxacin, and pefloxacin groups (p < 0.001, p < 0.05 and p < 0.01, respectively). Hyaline degeneration and fibre disarrangement were observed in the tendons of the ciprofloxacin, pefloxacin, and ofloxacin treated-groups, whereas myxomatous degeneration was observed only in the ciprofloxacin and pefloxacin groups. In conclusion, these findings in our rat model reveal significant deterioration of biomechanical parameters following fluoroquinolone exposure, and indicate significantly higher biomechanical toxicity for ciprofloxacin and pefloxacin

Dual Akt and Bcl-2 inhibition induces cell-type specific modulation of apoptotic and autophagic signaling in castration resistant prostate cancer cell lines

Background Cancer cell survival depends on the cross-regulation between apoptosis and autophagy which share common signaling pathways including PI3K/Akt/mTOR and Bcl-2. The aim of this study was to elucidate the modulation patterns between apoptosis and autophagy following dual inhibition by Akt inhibitor erufosine and Bcl-2 inhibitor ABT-737 in castration-resistant prostate cancer (CRPC) cell lines, PC-3 (Bax+) and DU-145 (Bax-). Methods and Results Cell cycle progression, apoptotic and autophagic signaling were examined by flow cytometry, multi-caspase assay, Hoechst staining, acridine orange staining of acidic vesicular organelles (AVOs), qRT-PCR and Western Blot. Dual inhibition increased G2/M arrest in PC-3 and DU-145, but not in the healthy prostate epithelium cells, PNT-1A. Only in PC-3, dual inhibition induced synergistic apoptotic and additive autophagic effects. In DU-145 and PNT-1A cells, ABT-737 did not display any remarkable effect on multicaspase activity and erufosine and ABT-737, neither alone nor in combination induced AVOs. By dual inhibition, AKT, BCL-2 and NF-kappa B gene expressions were downregulated in PC-3, both ATG-5 and BECLIN-1 gene expressions were upregulated in DU-145 but Beclin-1 protein expression was substantially reduced in both CRPC cells. Dual inhibition-induced synergistic multicaspase activation in PC-3 degrades and disrupts autophagic activity of Beclin-1, enhancing caspase-dependent apoptosis. However, in DU-145, following dual inhibition, rate of multicaspase induction and apoptosis are lower but autophagy is completely abolished despite markedly increased BECLIN-1 gene expression. Conclusion In conclusion, antineoplastic drug combinations may display cell-type specific modulation of apoptotic and autophagic signaling and lack of protective autophagy may not necessarily indicate increased chemotherapeutic sensitivity in heterogenous tumor subpopulations