Browsing by Author "Gürcü, B"

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    Histochemical determination of glycosaminoglycans (GAGs) in normal and ethanol-induced chick embryo during neural tube development
    Aydemir, I; Gürcü, B
    Alcohol as a teratogenic agent inhibits cell growth, function, proliferation and migration by affecting macromolecules, and can induce cell death. Prenatal ethanol exposure causes neural tube defects (NTD) and growth deficiency in experimental animals. NTDs are a group of malformations that result in failure of neural tube (NT) closure in early embryonic development and are among the most common congenital malformations in humans. NTDs are also associated with a number of other central nervous system malformations. Basal layers are the most densely stained structures with Alcian blue which determines glycosaminoglycan (GAG) types. While all sulphated GAGs were observed in the basal layers of NT of the embryos in control and saline-injected groups, hyaluronic acid was dominant in the 10% alcohol-administered embryos. It was reduced in the 15% alcohol-administered embryos and keratan sulphate was significantly low in 20% samples. Especially in the control and saline-injected groups, chondroitin sulphate and dermatan sulphate were highly expressed around cells migrating from the NT, while the same were reduced in 10% alcohol-administered embryos. In 15% alcohol-administered embryos, while the heparine and heparane sulphate were dense around cells migrating from the NT, staining specificities were decreased in 20% alcohol-administered embryos in same regions. Increased alcohol degrees cause decrease of the GAG types in both areas.
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    Effects of alcohol during secondary neurulation in chick embryos
    Mete, M; Aydemir, I; Ünsal, ÜÜ; Özbilgin, K; Tuglu, MI; Gürcü, B
    Objective: Alcohol continues to be consumed even though its harmful effecs are well established. One of the most common damage of alcohol consumption is fetal alcohol syndrome, characterized by craniofacial anomalies, cardiac anomalies and neural tube defects. Therefore, understanding the molecular mechanisms underlying the alcohol-induced toxicity that occur with time and dose dependent manner is very important., Most of the studies in order to understand the effects of alcohol have been carried out on early neurulation, however its effects on late neurulation are still unknown. Therefore in this study, effects of alcohol on secondary neurulation were investigated in chick embryos. Methods: Leghorn breed of embryonic chicken eggs were used. At 50 h of incubation, 100 mu L 50% ethanol solution was injected. Depending on the period of exposure to alcohol, varying degrees of pathological disorders were detected in E3, E7 and E10 days. Results: Developmental delay, structural abnormalities, morphological abnormalities in the heart and face and especially presence of two spinal cord cavities were found. In addition, we also detected delays in the closure of the neural tube, cellular deformities and the structural abnormalities in notochord. While eNOS, iNOS, and TUNEL levels increased, while laminin levels decreased. Conclusion: In this study during late development, significant alcohol-induced morphological and histopathological changes were observed. We also determined Increased level of oxidative stress caused by alcohol was accompanied with the changes in matrix composition. Better understanding of these mechanisms which affect the cell behavior is important and will allow learning of harmful effects of alcohol.
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    Genotoxic Effect, Oxidative Stress and Cell Death due to Metronidazole Application in Gills and Liver Tissues of Rainbow Trout (Oncorhynchus mykiss)
    Gürcü, B; Koca, S; Koca, YB; Çöllü, F; Tuglu, MI
    In this study, the purpose was to investigate the histopathological, genotoxic effect, oxidative stress and cell death due to Metronidazole (MTZ), which is a 5-nitroimidazole compound, used widely for the treatment of anaerobic organism infections in fish and humans on gill and liver tissues of Oncorhynchus mykiss. Trout fishes were exposed to 5, 10, and 20 mg/L of MTZ in the aquariums for 2, 4 and 8 days. Staining technics namely H&E, NOS immunohistochemistry, and TUNEL were performed to determine histopathological changes, oxidative damage and apoptosis. Additionally, smear preparations were also prepared from gill blood for genotoxic evaluations. The organ damage started in the 2(nd) day with 5 mg/L MTZ application and effects increased per duration and dose-dependent manner. It was observed that the gills had the primary and secondary lamellae lengths, with formation of clavate lamellae, fusion in secondary lamellae, separation of epithelium and aneurysm. Regional necrosis, vacuolization of hepatocytes, pycnotic nucleus, enlarged sinusoids were also determined in the liver. NOS immunoreactivity increased with the inducible immunoreactivity (iNOS) that was more prominent when compared to the endothelial immunoreactivity (eNOS). Apoptotic immunoreactivity was higher in the 10 mg 8(th) day experimental group at liver and gills, and was lower 20 mg 8(th) day experimental group. When the gills and liver compared with each other, in all doses, immunoreactivity was lower in gills, compared with liver. Genotoxic examinations showed that both number of micro nucleated erythrocytes and nuclei abnormalities were higher in MTZ-treated groups.
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    MORPHOLOGICAL AND HISTOCHEMICAL INVESTIGATIONS OF ESOPHAGOGASTRIC TRACT OF A LIZARD, LAUDAKIA STELLIO (AGAMIDAE, LINNAEUS 1758)
    Koca, YB; Gürcü, B
    Histological structures of esophagus and stomach tissue samples of Lacerta stellio have been studied, and glycosaminoglycan (GAG) distribution has been histochemically determined. Histologically, esophagus and stomach of L. stellio are composed of four layers: mucosa, submucosa, muscularis mucosae and serosa. Mucosa of esophagus is covered by simple columnar ciliated epithelium with many mucous secreting goblet cells and contains branched tubular glands. Stomach of L. stellio is composed of fundus (oral and aboral) and pylorus regions. Mucosa is covered by columnar epithelium. Fundic glands are branched tubular glands while pyloric glands are usually simple tubular glands. In both regions of the stomach, glands are subdivided into three areas as base, neck and isthmus. Both in the esophagus and stomach, muscular layer is in the form of smooth muscle having inner circular and outer longitudinal layers. According to the results obtained by Alcian Blue (pH 5.8)/Periodic Acid Schiff staining, stomach is similar to esophagus in that neutral mucins and hyaluronic acid (HA) are dominant in isthmus and neck regions of gland tissue of stomach. In the base of the stomach, only neutral mucins have been observed. HA has been observed to be dominant in all other regions of both stomach and esophagus, along with some but not much sulphated GAGs.
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    Matrix changes due to the toxic effects of metronidazole in intestinal tissue of fish (Onchorhynchus mykiss)
    Gürcü, B; Koca, YB; Özkut, M; Tuglu, MI
    Metranidazole (MTZ) is an antibiotic used for parasitic infections in a number of species. Accumulation of this drug in the environment and its interaction with fish of economic value makes this drug particularly important. In the present study, we examined the histopathological effects of MTZ on the intestinal tissue of Oncorhynchus mykiss. The fish in aquarium were exposed to MTZ at doses of 5, 10, 20 mg/L for 2, 4 and 8 days. At the end of the experiments, macroscopic pathology or death were not observed at these doses. Histochemical staining with Haematoxylene-Eosin, Periodic Acid Schiff and Gomori Trichrome showed, depending on increased dose and prolonged duration, areas of necrosis, edema, inflammation, small tears at the tips of the villi and excretion with heterogenic distribution of the Goblet cells. Moreover, changes in the connective tissue of the intestines due to toxicity of MTZ and decreases in immunostaining of matrix proteins such as laminin and collagen IV, especially in the epithelium were observed. Findings of the present study would be useful to demonstrate the adverse effects of MTZ use, emphasizing the importance of the effect on fish which could be very important public health. (C) 2015 Elsevier Ltd. All rights reserved.
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    Genotoxic and histopathological effects of water pollution on two fish species, Barbus capito pectoralis and Chondrostoma nasus in the Buyuk Menderes River, Turkey
    Koca, S; Koca, YB; Yildiz, S; Gürcü, B
    The genotoxic and histopathological effects of water pollution were investigated on two fish species caught from the Buyuk Menderes River and from its tributary, the Cine Stream. The Buyuk Menderes basin is an important agricultural area in Turkey. The levels of copper, zinc, cadmium, cobalt, and lead were measured at the surface of the water and in gills, liver, and muscle tissue of Chondrostoma nasus and Barbus capito pectoralis. In some tissues, the concentrations of some of these metals exceeded acceptable levels for human consumption. Zinc was found to be the most abundant metal in water and tissues. Maximal metal accumulation was observed in the liver. To detect the genotoxic potential of contaminants, the formation of micronucleus in erythrocytes was used as indicator of chromosomal damage. The frequency of micronucleus formation did not show significant differences between locations and controls in B. capito pectoralis caught from three locations and C. nasus from two locations. The histological changes included significant decreases of the mean lengths of primary and secondary lamellae. In gills epithelia, we observed cellular proliferation that developed Because of secondary lamellae fusion, ballooning degenerations, or club deformation of secondary lamellae and cystic structures in secondary lamellae. In the liver, the changes included swollen and ruptured parenchymal cells, loss of cord structure, vacuoles filled with cellular debris, focal necrosis, and a significant increase in Kupffer cells.
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    Investigation of histopathological and cytogenetic effects on Lepomis gibbosus (Pisces: Perciformes) in the Cine Stream (Aydin/Turkey) with determination of water pollution
    Koca, YB; Koca, S; Yildiz, S; Gürcü, B; Osanç, E; Tunçbas, O; Aksoy, G
    Water quality and the distribution of some heavy metals in three different organs of Lepomis gibbosus from the Cine Stream were studied. Also, histopathological changes in gill, liver, and muscle tissue were examined at light microscopical level. Micronucleus (MN) formation in fish erytrocytes, as an indicator of chromosomal damage, has been increasingly used to detect the genotoxic potential of environmental contaminants. The frequency of MN was examined from samples of fish from the Cine Stream and a control group. MN frequency was higher in fish samples caught from the Cine Stream than that in the control group. The chemicals ammonia, nitrite, nitrate, orthophosphate, and sulphate were determined as parameters that possibly affect the gill, liver, and muscle morphology. Zn was the most accumulated metal in tissues as well as in water. Maximum metal accumulation occured in both liver and gills. For histopathological examinations, samples of gills, liver, and muscle tissues of L. gibbosus were studied by using light microscopy. In this study, a significant decrease in mean length of primary and secondary lamellae were observed. Moreover, cellular proliferation developed with secondary lamellae fusion, ballooning degenerations or club deformation of secondary lamellae, as well as distribution of necrotic, hyperplastic and clavate secondary lamellae. In the liver, altered staining, swollen and ruptured parenchymal cells, loss of cord structure, reduce of glycogen in hepatocytes, and vacuolar structure filled with cellular debris and many dark particles were seen. In muscle tissue, focal necrosis, cellular dissolution, and a decline or loss of striatation in muscle fibres were found. (C) 2005 Wiley Periodicals, Inc.
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    Prion protein-dependent regulation of p53-MDM2 crosstalk during endoplasmic reticulum stress and doxorubicin treatments might be essential for cell fate in human breast cancer cell line, MCF-7
    Tugrul, B; Balcan, E; Öztel, Z; Çöllü, F; Gürcü, B
    In this study, we investigated the effect of doxorubicin and tunicamycin treatment alone or in combination on MDM-, Cul9-and prion protein (PrP)-mediated subcellular regulation of p53 in the context of apoptosis and autophagy. MTT analysis was performed to determine the cytotoxic effect of the agents. Apoptosis was monitorized by ELISA, flow cytometry and JC-1 assay. Monodansylcadaverine assay was performed for autophagy. Western blotting and immunofluorescence were performed to determine p53, MDM2, CUL9 and PrP levels. Doxorubicin increased p53, MDM2 and CUL9 levels in a dose-dependent manner. Expression of p53 and MDM2 was higher at the 0.25 & mu;M concentration of tunicamycin compared to the control, but it decreased at 0.5 & mu;M and 1 & mu;M concentrations. CUL9 expression was significantly decreased only after treatment of tunicamycin at 0.25 & mu;M. According to its glycosylation status, the upper band of PrP increased only in combination treatment. In combination treatment, p53 expression was higher than control, whereas MDM2 and CUL9 expressions were decreased. Combination treatments may make MCF-7 cells more susceptible to apoptosis rather than autophagy. In conclusion, PrP may be important in determining the fate of cell death through crosstalk between proteins such as p53 and MDM2 under endoplasmic reticulum (ER) stress conditions. Further studies are needed to obtain in-depth information on these potential molecular networks.
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