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    Effect of the preservation-to-surgery interval on corneal allograft survival in low-risk patients
    (Slack Inc, 2007) Doganay, Selim; Hepsen, I. Fevzi; Yologlu, Saim; Demirtas, Hakan
    m BACKGROUND AND OBJECTIVE: To investigate the role of the preservation-to-surgery interval on corneal allograft survival in low-risk patients. PATIENTS AND METHODS: Eighteen donor corneas obtained from an overseas eye bank were preserved and transported overseas in Optisol-GS solution (Chiron Vision, Irvine, CA) in Group 1. Thirty fresh, young, healthy, and unscreened donor corneas soaked in the same medium were used in Group 2. Average preservation-to-surgery time was more than 8 days in Group 1 and less than 30 hours in Group 2. Corneal allograft survival rates were determined by Kaplan-Meier estimates of the survivor functions. The log-rank test was used to determine statistical significance of the differences between groups. RESULTS: The mean preservation-to-surgery interval was 233.3 +/- 37.7 hours in Group I and 20.8 +/- 4.6 hours in Group 2 (P <.05 for the comparison of average times). There were significant differences between the groups with respect to donors' age and enucleation time, but there were no statistically significant differences between the groups in terms of graft diameter and recipient diameter or for corneal allograft survival in low-risk patients. The graft survival rate was 83.3% in Group I and 93.3% in Group 2 at the end of the follow-up period. CONCLUSIONS: Preservation-to-surgery time has no effect on corneal allograft survival in low-risk patients. However, prospective, randomized, long-term and large-scale clinical trials are necessary to confirm these findings.
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    Investigation of a weak magnetic field effect on the in vitro catalytic activity of adenosine deaminase and xanthine oxidase
    (General Physiol And Biophysics, 2011) Batcioglu, Kadir; Dogan, Metin; Uyumlu, Ayse B.; Satilmis, Basri; Bayri, Nevzat; Atalay, Selcuk; Demirtas, Hakan
    The effect of a weak magnetic field (MF) on adenosine deaminase (ADA) and xanthine oxidase (XOD) activities have been investigated. A 50 Hz uniform MF was generated, and the magnitude of the field was kept constant at 5.8 mT. The changes in ADA activity over time were significantly different in and out of the MF; MF caused a steeper decline in ADA activity compared to the situation when no MF is present. In addition, MF caused a significant increase in XOD activity. There were no significant time-related changes for either enzyme in the absence of the MF. We suggest that a weak MF affects enzymatic systems.
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    Oxidative Stress in the in vivo DMBA Rat Model of Breast Cancer: Suppression by a Voltage-gated Sodium Channel Inhibitor (RS100642)
    (Wiley, 2012) Batcioglu, Kadir; Uyumlu, A. Burcin; Satilmis, Basri; Yildirim, Battal; Yucel, Neslihan; Demirtas, Hakan; Onkal, Rustem
    Breast cancer (BCa) was induced in vivo in female rats with 7,12-dimethylbenz(a)anthracene (DMBA). Two main questions were addressed. Firstly, would the carcinogenesis be accompanied by oxidative stress as signalled by superoxide dismutase, glutathione peroxidase, malondialdehyde and total nitrate? Secondly, would treating the rats additionally with a blocker of voltage-gated sodium channel (VGSC) activity, shown previously to promote BCa progression, affect the oxidative responses? The DMBA-induced increases in the antioxidant systems were completely blocked by the VGSC inhibitor RS100642, which also significantly prolonged the lifespan. We conclude that VGSC inhibition in vivo can significantly protect against oxidative stress and improve survival from tumour burden.