Browsing by Author "Simsek, Nejdet"

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Effects of Spirulina on the Number of Ovary Mast Cells in Lead-Induced Toxicity in Rats
(John Wiley & Sons Ltd, 2007) Karaca, Turan; Simsek, Nejdet
The present study investigated the protective effect of Spirulina against the lead-induced increase in mast cells in the ovary during the oestrous cycle of rats. In the ovary cortex and medulla of lead-exposed animals, there was a significant increase in the number of mast cells; however, when also treated with Spirulina, a decrease was observed. The number of mast cells when Spirulina (300 mg/kg) was used alone was not significantly different from that of the control group. These results indicate that Spirulina decreases the number of mast cells induced by lead in the cortex and medulla of rat ovary. Copyright (c) 2006 John Wiley & Sons, Ltd.
Immunohistochemical Distribution of Glucagon -, Insulin -, Somatostatin -, Gastrin-, and Serotonin-Containing Cells in the Pancreas of the Van Cat
(Tubitak Scientific & Technological Research Council Turkey, 2014) Karaca, Turan; Kara, Adem; Simsek, Nejdet; Uslu, Sema; Tekiner, Deniz; Yoruk, Mecit
The regional distribution, relative frequency, and appearance of glucagon (A-cell)-, insulin (B-cell)-, somatostatin (D-cell)-, gastrin (G-cell)-, and serotonin (EC-cell)-secreting cells in the endocrine and exocrine pancreas of Van cats were examined using the immunohistochemistry method. Glucagon immunopositive A-cells were principally found in the central region of the islets of Langerhans, while insulin immunopositive B-cells were located in the periphery of the pancreatic islets. Moreover, several A- and B-cells were observed as only single cells or clusters of 2 to 3 immunopositive cells in the exocrine parenchyma and the pancreatic duct epithelium. Somatostatin and gastrin immunopositive reactivities were negligible in the peripheral regions of the pancreatic islets of Langerhans and in the exocrine parenchyma. However, serotonin-immunopositive EC-cells were observed in neither the endocrine islets nor any other sites of the tissue. The existence, regional distribution, and relative frequency of A-, B-, D-, G- and EC-cells in the pancreas of Van cats have been analyzed in this study for the first time. The immunopositivity and distribution of endocrine cells in the Van cat pancreas were determined to be partially different from those of other carnivorous species such as dogs and other cats.
Royal Jelly Modulates Oxidative Stress and Apoptosis in Liver and Kidneys of Rats Treated With Cisplatin
(Hindawi Ltd, 2011) Karadeniz, Ali; Simsek, Nejdet; Karakus, Emre; Yildirim, Serap; Kara, Adem; Can, Ismail; Turkeli, Mehmet
Cisplatin (CDDP) is one of the most active cytotoxic agents in the treatment of cancer and has adverse side effects such as nephrotoxicity and hepatotoxicity. The present study was designed to determine the effects of royal jelly (RJ) against oxidative stress caused by CDDP injury of the kidneys and liver, by measuring tissue biochemical and antioxidant parameters and investigating apoptosis immunohistochemically. Twenty-four Sprague Dawley rats were divided into four groups, group C: control group received 0.9% saline; group CDDP: injected i.p. with cisplatin (CDDP, 7 mg kg(-1) body weight i.p., single dose); group RJ: treated for 15 consecutive days by gavage with RJ (300 mg/kg/day); group RJ + CDDP: treated by gavage with RJ 15 days following a single injection of CDDP. Malondialdehyde (MDA) and glutathione (GSH) levels, glutathione S-transferase (GST), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) activities were determined in liver and kidney homogenates, and the liver and kidney were also histologically examined. RJ elicited a significant protective effect towards liver and kidney by decreasing the level of lipid peroxidation (MDA), elevating the level of GSH, and increasing the activities of GST, GSH-Px, and SOD. In the immunohistochemical examinations were observed significantly enhanced apoptotic cell numbers and degenerative changes by cisplatin, but these histological changes were lower in the liver and kidney tissues of RJ + CDDP group. Besides, treatment with RJ lead to an increase in antiapoptotic activity hepatocytes and tubular epithelium. In conclusion, RJ may be used in combination with cisplatin in chemotherapy to improve cisplatin-induced oxidative stress parameters and apoptotic activity.