Beyhan Gürcü

Genotoxic and histopathological effects of water pollution on two fish species, Barbus capito pectoralis and Chondrostoma nasus in the Büyük Menderes River, Turkey.

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.

Matrix changes due to the toxic effects of metronidazole in intestinal tissue of fish (Onchorhynchus mykiss)

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.

Neuroprotective effects of oleocanthal, a compound in virgin olive oil, in a rat model of traumatic brain injury

AIM To evaluate the neuroprotective effects of deocanthal OC in a rat model of traumatic brain injury (TBI). MATERIAL AND METHODS Twenty-six adult male, Wistar albino rats were used. The rats were divided into 4 groups. Group 1 was the sham group (n=5). Group 2 was the trauma group (n=5) where rats were treated with 10 mg/kg saline intraperitoneally (IP) twice a day. Groups 3 and 4, rats were treated with 10 (group 3, n=8) or 30 (group 4, n=8) mg/kg OC IP twice a day. For each group, brain samples were collected 72 hours after injury. Brain samples and blood were evaluated with histopathological and biochemical methods. RESULTS Histopathological evaluation revealed a significant difference between Group 2 and Group 4. Biochemical findings demonstrated that the oxidative stress index was highest in Group 2 and lowest in Group 4. CONCLUSION OC has a protective effect on neural cells after TBI. This effect is achieved by reducing oxidative stress and apoptosis.

Morphological and histochemical investigations of esophagogastric tract of a lizard, Laudakia stellio (Agamidae, Linnaeus 1758)

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.

Histological structure of the skin of the Southern Crested Newt, Triturus karelinii (Salamandridae: Urodela)

Abstract The histological structure of the skin of the Southern Crested Newt, Triturus karelinii, from the active aquatic period has been studied by different staining methods. The species has two main layers: epidermis and dermis. The epidermal layer contains stratum germinativum and stratum corneum; the dermal layer stratum spongiosum and stratum compactum. The dermis has a connective tissue structure and contains large amounts of chromatophores and secretory glands. While the stratum compactum of the dermis contains collagen fibres, the basal laminae of the epidermal stratum germinativum cells, apical facies of the stratum corneum cells and the dermal ground substances contain glycosaminoglycan structures. By using computerized image processing software, the thickness of the epidermis and dermis has been measured and the amount of collagen fibres in terms of chosen point determined. We conclude that the extracellular matrix of the T. karelinii skin is largely comprised of two structurally distinct molecular components: collagen and glycosaminoglycans, but the amount of these components may be different in the water and land periods, depending upon the activity of these amphibians.