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Öğe Cytochrome P450 aromatase expression in canine nervous tissue: an immunohistochemical study(Polish Acad Sciences, Committee Veterinary Sciences, 2008) Karahan, S.; Yarim, M.; Harada, N.The enzyme cytochrome P450 aromatase is responsible for conversion of androgens to estrogens. Estrogens have been implicated in neurophysiology and neuropathology. The present study investigated the presence of aromatase immuno reactivity in the temporal, parietal and occipital cortices, olfactory bulb, cerebellum, and choroid plexus of the normal dog. Aromatase immunoreactivity was localized exclusively in neurons in the cortices and olfactory bulb. Immunoreactivity was also present in a small number of astrocytes in the substantia alba of the cerebellum. In the cortical regions, immunoreactive neurons, morphologically identified as pyramidal cells, were found throughout Layer 11 down to Layer VI, but not all pyramidal neurons were immunoreactive. In the olfactory bulb, immunoreactive neurons were mainly observed in mitral cells and inner granular cell layers. In the cerebellum, immunoreactivity was present in neurons of the deep cerebellar nuclei and in some neurons of the molecular and granular cell layers. Immunoreactivity was also present in endothelial cells of the subarachnoid vessels and those adjacent to ventricles in the cortex. The presence of well defined cytoplasmic aromatase immunoreactivity in neurons, some astrocytes, and endothelial cells suggests estrogen involvement in CNS physiology and function in the dog. The presence of aromatase in ependymal cells lining cerebral ventricles and choroid epithelial cells suggests that these cells may be partially responsible for estrogen concentration in the cerebrospinal fluid.Öğe Elevated plasma levels of interleukin 1β, tumour necrosis factor α and monocyte chemotactic protein 1 are associated with pregnancy toxaemia in ewes(Springer, 2007) Yarim, G. F.; Karahan, S.; Nisbet, C.Pregnancy toxaemia is a metabolic disorder that results from an inadequate energy supply to the growing maternal-fetal unit. The mechanism underlying the pathogenesis of the syndrome has not been fully clarified; however, a key role for cytokines and chemokines including interleukin 1 beta (IL-1 beta), tumour necrosis factor alpha (TNF-alpha) and monocyte chemotactic protein 1 (MCP-1) has been indicated in women and experimental animals. However, information on the maternal plasma levels of IL-1 beta, TNF-alpha and MCP-1 in ewes with pregnancy toxaemia is limited. Thus, the present study was designed to determine plasma IL-1 beta, TNF-alpha and MCP-1 concentrations in ewes with severe (n = 6) and mild (n = 4) naturally occurring pregnancy toxaemia and in uncomplicated pregnant ewes (n = 10) using enzyme-linked immunosorbent assay (ELISA). All ewes with pregnancy toxaemia had significantly lower body temperature and respiratory rate than uncomplicated pregnant ewes (p < 0.05). With the highest concentrations in severe cases, heart rate, proteinuria and serum uric acid levels as well as plasma IL-1 beta, TNF-alpha and MCP-1 were significantly different among all three groups (p < 0.05). The plasma concentrations of IL-1 beta in control ewes and ewes with mild and severe toxaemia were 15.81 +/- 3.90 pg/ml, 23.83 +/- 2.42 pg/ml and 34.55 +/- 8.03 pg/ml, respectively. The plasma concentrations of TNF-alpha in control ewes and ewes with mild and severe toxaemia were 7.71 +/- 1.61 pg/ml, 16.13 +/- 3.63 pg/ml, and 22.85 +/- 3.64 pg/ml, respectively. The plasma concentrations of MCP-1 in control ewes and ewes with mild and severe toxaemia were 101.70 +/- 9.86 pg/ml, 134.75 +/- 6.24 pg/ml, and 157.67 +/- 9.69 pg/ml, respectively. Moreover, plasma IL-1 beta, TNF-alpha and MCP-1 levels were positively correlated with clinical and well-establish biochemical parameters of pregnancy toxaemia, serum uric acid and proteinuria (p < 0.01). Concomitant increase of plasma IL-1 beta, TNF-alpha and MCP-1 concentrations along with serum uric acid, proteinuria, and worsening of the clinical signs indicates that such cytokines are involved in the aetiopathogenesis and in perpetuation of the local and systemic inflammatory reactions in pregnancy toxaemia in ewes. Hence, plasma IL-1 beta, TNF-alpha and MCP-1 may potentially serve as markers to monitor prognosis of pregnancy toxaemia in ewes.Öğe The fine structures of Cystocaulus ocreatus (Nematoda : Protostrongylidae) and the related lung pathology(Versita, 2006) Yıldız, K.; Karahan, S.; Çavuşoğlu, K.In the present study, the fine surface structures of Cystocaulus ocreatus and its worm as well as brood nodules obtained from the lung of Akkaraman sheep are demonstrated by scanning electron and light microscopy. The mouth of the parasite obtained from the worm nodules is located at the anterior tip and encircled by a collar of tissue. The mouth opening appears as three slits conjoined in the shape of a capital case letter Y, creating three lips. The mouth is surrounded by six papillae just behind the collar. The anterior end was similar in both sexes and covered by numerous wrinkles. Female parasite has a bell-shaped pro-vagina. The posterior end of the female parasite was sharply pointed. The male parasite has a bursa. In the worm nodule, curled parasites were enclosed by a capsula and no eggs and larvae of the parasite were observed. In the brood nodule, heavily affected alveoli and bronchioles contained excessive amounts of larvae and eggs.Öğe In vitro and in vivo Performance of Polyethyleneimine (PEI) Brushes Integrated on Polyurethane (PU) Ureteral Stents Against Biofilm Formation and Encrustation(Mary Ann Liebert, Inc, 2015) Gultekinoglu, M.; Kürüm, Barış; Karahan, S.; Kart, D.; Sagiroglu, M.; Ozen, H.; Ulubayram, K.…Öğe Proliferative response by the ostrich proventriculus in idiopathic gastric stasis: A case report(Akademiai Kiado, 2006) Öcal, N.; Karahan, S.; Atmaca, T.In this report, the late clinical, necropsy, and histopathological findings of idiopathic gastric stasis in an ostrich are described, with special attention to the proventriculus. An ostrich with clinical signs of gastric stasis was brought to our clinic in a state of impending death that could not be reversed with emergency medical care. At necropsy, the koilin layer of the gizzard was uneven without ulcerations. The proventriculus was distended with food items without impaction and mucosal lesions. None of the most typical aetiological factors including foreign objects, Macrorhabdus ornithogaster and parasitic infection with Libyostrongylus douglassii was present. Histologically, the proventriculus was characterised by hyperplastic mucosa with luminal buds and necrotic cells in the lumen. Immunochemistry for proliferating cell nuclear antigen ( PCNA) revealed a high rate of proliferation in epithelial cells of the glandular and mucosal lining in the proventriculus neighbouring the affected gizzard: approximately 88.6% of the cells were immunoreactive as compared to 34.4% of the cells in control ostriches used for comparison. In conclusion, in the absence of gizzard contraction, the mucosal lining of the proventriculus is hyperplastic with a high rate of proliferation that may help compensate the distension due to the accumulation of food items.Öğe Regional brain and sex differences in the plasma progesterone concentration of sheep(Elsevier Science Bv, 2007) Yarim, G. F.; Karahan, S.Progesterone concentration was measured in specific brain regions of the ram and anestrous ewe to provide reference values for future studies to investigate if local CNS lesions resulting from neurodegenerative diseases of sheep are associated with progesterone loss. Using radioimmunoassay, plasma progesterone was recorded throughout all brain regions assayed. No significant differences were found between the ewe and ram for any brain regions. There were however, significant differences between the different regions of an individual brain (P < 0.05). Plasma progesterome concentration for the highest to the lowest value recorded was as follows: 2.93 +/- 0.85 and 2.77 +/- 0.51 ng/g in the frontal cortex; 2.33 +/- 0.67 and 2.25 +/- 0.48 ng/g in the parietal cortex; 1.32 +/- 0.36 and 1.29 +/- 0.35 ng/g in the temporal cortex; 1.25 +/- 0.32 and 1.25 +/- 0.31 ng/g in the occipital cortex; 1.24 +/- 0.30 and 1.23 +/- 0.31 ng/g in the corpus callosum; 1.16 +/- 0.30 and 1.21 +/- 10.38 ng/g in the cerebellum; 1.09 +/- 0.30 and 1.12 +/- 0.39 ng/g in the medulla oblongata of the ewe and ram, respectively. Plasma progesterone concentration in the ewe (0.28 +/- 0.06 ng/ml) was significantly higher than that in the ram (0.10 +/- 0.03 ng/ml) (P < 0.001). Furthermore, plasma progesterone concentration in all sheep was several times lower than that of any regions of the brain. The results indicate that the sheep brain accumulates progesterone in significant levels, which may be independent of the circulating progesterone. The brain progesterone concentration in CNS regions assayed was similar for the ram and anestrous ewe. Neurodegenerative processes in visna, border disease and enzootic ataxia should be questioned in further studies if they are associated with local progesterone loss. (C) 2006 Elsevier B.V. All rights reserved.Öğe The scanning electron and light microscopic structure of bovine tactile hair(Blackwell Verlag Gmbh, 2004) Yildiz, D.; Gultiken, M.E.; Karahan, S.Bovine tactile hairs in skin samples from the lateral side of the upper lip were examined using scanning electron and light microscopy. The root of these hairs has a variable length and is surrounded by a large sinus located between the internal and the external dermal sheath. With a prominent thickness, the external dermal sheath forms the external wall of the tactile hair and contains many nerves some of which extend into trabeculae. Trabeculae projecting from the internal dermal sheath and attaching to the external dermal sheath with two or more branches are present in the entire sinus. The trabeculae are interconnected by connective tissue sheets that support the integrity of the trabecular organization. The sinus surfaces as well as trabeculae are lined by endothelia. As a result, the bovine tactile hair is truly a cavernous type of tactile hair with a well organized microscopic anatomy. Thus, the bovine tactile hair most likely plays an important role in relatively immobile and insensitive bovine lips.
