Yazar "Birhanli, Ayse" seçeneğine göre listele
Listeleniyor 1 - 4 / 4
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe ASSESSMENT OF EMBRYOTOXIC EFFECTS OF CADMIUM, LEAD AND COPPER ON Xenopus laevis(Parlar Scientific Publications (P S P), 2010) Gungordu, Abbas; Birhanli, Ayse; Ozmen, MuratThis work evaluated the effects of selected metals on embryos using Frog Embryo Teratogenesis Assay- Xenopus (FETAX). Besides FETAX parameters, changes in several biomarkers were studied as early signs of intoxication on Xenopus laevis tadpoles. The acute effects of metals were investigated by using the activity of the enzymes glutathione S-transferase (GST), glutathione reductase, acetylcholinesterase (AChE), carboxylesterase, lactate dehydrogenase, aspartate aminotranferase, and alanine aminotranferase. In the FETAX test, 96-h LC50s were determined as 1.6 mg/L, 96.1 mg/L, and 1.37 mg/L for Cd, Pb, and Cu, respectively. Also, teratogenic index (TI) of each metal was estimated as 1.1, 1.22, and 0.52 for Cd, Pb, and Cu, respectively. The TI showed that tested metals were not teratogenic in X. laevis embryos according to ASTM values. The comparison of selected metals on selected enzyme activities was expected to give useful indications for the proper use of biochemical responses as biomarkers.Öğe Biochemical response to exposure to six textile dyes in early developmental stages of Xenopus laevis(Springer Heidelberg, 2013) Gungordu, Abbas; Birhanli, Ayse; Ozmen, MuratThe present study was undertaken to determine the toxic effect of a lethal concentration of six different commercially used textile dyes on the 46th stage of Xenopus laevis tadpoles. The tadpoles were exposed to Astrazon Red FBL, Astrazon Blue FGRL, Remazol Red RR, Remazol Turquoise Blue G-A, Cibacron Red FN-3G, and Cibacron Blue FN-R for 168 h in static test conditions, and thus, 168-h median lethal concentrations (LC(50)s) of each dye were determined to be 0.35, 0.13, 112, 7, 359, and 15.8 mg/L, respectively. Also, to evaluate the sublethal effects of each dye, tadpoles were exposed to different concentrations of dyes (with respect to 168-h LC(50)s) for 24 h. The alteration of selected enzyme activities was tested. For this aim, glutathione S-transferase (GST), carboxylesterase, and lactate dehydrogenase (LDH) were assayed. After dye exposure, the GST induction or inhibition and LDH induction indicated some possible mechanisms of oxidative stress and deterioration in aerobic respiration processes induced by the tested dyes. Findings of the study suggest that selected biomarker enzymes are useful in understanding the toxic mechanisms of these dyes in X. laevis tadpoles as early warning indicators. Therefore, these selected biomarkers may evaluate the effect of environmental factors, such as textile dye effluents and other industrial pollutants, on amphibians in biomonitoring studies.Öğe Effect of nanosized TiO2 particles on the development of Xenopus laevis embryos(TUBITAK SCIENTIFIC & TECHNICAL RESEARCH COUNCIL TURKEY,, 2014) Birhanli, Ayse; Emre, Fatma Bilge; Sayilkan, Funda; Gungordu, AbbasThis paper reports the toxic properties of nano-TiO2 on 2 different early life stages of Xenopus laevis. Synthesis of nano-TiO2 particles was carried out by the hydrothermal method. Characterization of nanoparticles was performed using spectral techniques including X-ray diffraction, scanning electron microscopy, and a particle-size analyzer. Embryos at the 8th stage and tadpoles at the 46th stage were exposed to 7 concentrations of nano-TiO2 in the range of 5 to 320 ppm. After 96 h of exposure, the mortality percentage of each exposure concentration was calculated and the activity of enzyme biomarkers acetylcholinesterase, carboxylesterase, glutathione S-transferase, glutathione reductase, lactate dehydrogenase, and aspartate aminotransferase were determined in living embryos and tadpoles. None of the tested concentrations of TiO2 caused statistically significant mortality or malformation (only for the embryo test) as compared to the control groups. Furthermore, we did not observe any significant changes in enzyme activities in tadpole samples from the 46th stage, although some minor changes not related to the concentrations were observed in embryos.Öğe Evaluation of in vitro and in vivo toxic effects of newly synthesized benzimidazole-based organophosphorus compounds(Academic Press Inc Elsevier Science, 2013) Gungordu, Abbas; Sireci, Nihat; Kucukbay, Hasan; Birhanli, Ayse; Ozmen, MuratThis paper reports the toxic properties of eight newly synthesized benzimidazole-based organophosphorus (OP) compounds in Xeno pus laevis in both in vivo and in vitro conditions. For both experiments, a commercial solution of azinphos methyl (AzM, Gusathion M WP25) was used as a reference compound. The 24-h median lethal concentrations (LC50) of all tested compounds were determined for 46th stage tadpoles in the range of 9.54-140.0 mu M. For evaluation of the lethality of the compounds, the activity of the enzyme biomarkers acetylcholinesterase (AChE), carboxylesterase, glutathione S-transferase (GST), glutathione peroxidase, glutathione reductase, lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase were determined in vivo in X. laevis tadpoles exposed to three concentrations (LC50, LC50/2, and LC50/4) of tested compounds. All exposure concentrations of AzM and seven of eight tested compounds caused CaE inhibition in in vivo conditions. Furthermore, the AChE inhibition capacity of tested compounds in commercial electric eel AChE and in X. laevis homogenates and also CaE inhibition capacity in only X. laevis homogenates were assayed for a 30-min in vitro exposure period. Eight OP compounds did not inhibit AChE activity more than 23 percent, but AzM exposure inhibited AChE activity by 26 percent for X. laevis homogenates and 97 percent for electric fish AChE in in vitro conditions. Also. CaE inhibition levels in X. laevis tadpole homogenates were 46 percent for AzM and between 8 percent and 33 percent for other compounds in in vitro conditions. (C) 2012 Elsevier Inc. All rights reserved.
