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Öğe Ankara tavşanlarında ekzokrin pankreasın histolojik yapısı(2009) Şimşek, Nejdet; Ergün, Emel; Ergün, LeventBu çalışmada, Ankara tavşanlarının ekzokrin pankreası ışık ve elektron mikroskobik olarak incelendi. Tavşanlardan alınan pankreas örnekleri bouin ve gluteraldehit-paraformaldehit solüsyonlarında tespit edildi. Daha sonra bu dokular histolojik yöntemlerle işlenerek paraplast ve araldit M’de bloklandı. Işık ve elektron mikroskobik incelemelerde, ekzokrin pankreast, asiner hücreler ile küçük, orta ve büyük çaplı akıtıcı kanallar oluşturuyordu. Asinusu meydana getiren piramidal epitel hücrelerinin granüllü endoplazmik retikulum, krista tipi mitokondriyon, serbest ribozom ve elektron yoğun zimogen salgı granüllerinden zengin olduğu saptandı. Orta ve büyük çaplı akıtıcı kanalların lamina epitelyalis’i çoğunlukla prensipal hücreler, çok sayıda goblet hücresi ve az sayıda enteroendokrin hücreler, lamina propriya’sı ise müköz ve serömüköz bezler içermekteydi. Sonuç olarak, Ankara tavşanlarında ekzokrin pankreasın histolojik yapısı insan, rat, fare ve kedi gibi memelilere benzese de, akıtıcı kanallarında goblet hücreleri, müköz ve sero-müköz bezleri içermesi nedeniyle diğer memeli türlerinden farklı olduğu saptanmıştır. Bu nötral, asidik ve miks müsin içeren hücre ve bezlerin Ankara tavşanlarında ekzokrin pankreasın salgı metabolizmasına yardımcı olabileceği düşünülmüştür.Öğe Ankara tavşanında endokrin pankreas üzerine ışık ve elektron mikroskobik araştırmalar(2010) Şimşek, Nejdet; Ergün, Emel; Ergün, LeventBu çalışmada, Ankara tavşanlarının (10 adet, sağlıklı ve erişkin) endokrin pankreası histokimyasal ve elektron mikroskobik olarak incelendi. Tavşanlardan alınan pankreas örnekleri Bouin, Carnoy ve gluteraldehit-paraformaldehit solüsyonlarında tespit edildi. Aldehit fuksin light green orange G (AF) ile histokimyasal olarak boyanan pankreas kesitlerinde 2 tip endokrin hücre belirlenmesine rağmen, elektron mikroskobik incelemelerde endokrin adacıkların A, B ve D hücrelerinden oluştuğu gözlendi. Langerhans adacıklarının merkezinde mor-menekşe boyanan çok sayıda B hücrelerinin ve periferinde sarımsı-yeşil boyanan az sayıda A hücrelerinin bulunduğu saptandı. Elektron mikroskobik olarak, A hücrelerinin salgı granülü genellikle yuvarlak ve elektron çok yoğun iken, B hücrelerinin sitoplazmasında salgı içeriği ile salgı membranı arasında belirgin boşluk bulunan elektron çok yoğun ve elektron az yoğun granüller tespit edildi. D hücrelerinin de elektron çok yoğun ve elektron az yoğun materyale sahip yuvarlak 2 çeşit granül içerdiği ancak, bu granüllerin A ve B hücrelerinin granüllerinden daha küçük olduğu gözlendi. Bu çalışmanın sonucunda, Ankara tavşanı endokrin pankreasının çok sayıda B hücreleri, az sayıda A hücreleri ve çok az sayıda da D hücrelerinden oluştuğu saptandı.Öğe Distribution and location of endocrine cells in the pancreas of the sparrowhawk, accipiter nisus(2014) Kara, Adem; Tekiner, Deniz; Şimşek, Nejdet; Balkaya, Hülya; Özüdoğru, ZekeriyaBu çalışmada, atmaca pankreasının dorsal, ventral ve splenik loblarında bulunan endokrin hücrelerin dağılımı immun- histokimysal metotlarla belirlenmiştir. Pankreas dokusu anti-glukagon, anti-insulin, anti-gastrin ve anti-somatostatin primer antikorları kullanılarak streptavidin-biotin peroxidase metodu ile boyandı. Çalışmada, glukagon (alfa hücresi), insülin (beta hücresi) ve somatostatin (delta hücresi) salgılayan hücrelerin splenik lobda sayısının en fazla olduğu saptandı. Atmalarda pankreasın endokrin bölümlerinin alfa, beta ve miks adacıklar halinde gruplaştıkları saptandı. Beta adacıklarının çok sayıda beta hücresi, az sayıda deltaalfa hücrelerini içerdiği belirlendi. Alfa adacıkları, genellikle alfa ve delta hücrelerinden nadiren de beta hücrelerinden oluşuyordu. Ayrıca, gastrin pozitif hücreler, sadece ekzokrin pankreasta 1 ya da 2-3 adet hücre grubu halinde bulunurken, seratonin pozitif hücrelere ise ekzokrin ve endokrin pankreasın herhangi bir bölümünde rastlanmadı. Sonuç olarak, atmaca pankreasının lop sayısı, endokrin adacık tipleri ve endokrin hücre lokalizasyonu açısından etçil kuşlarla benzerliği, evcil kuş türleriyle de farklılıkları belirlenmiştir.Öğe The effects of experimental aflatoxicosis on the exocrine pancreas in quails (Coturnix coturnix japonica)(Springer Heidelberg, 2007) Şimşek, Nejdet; Ergun, Levent; Ergun, Emel; Alabay, Belma; Essiz, DincThe present investigation was undertaken to assess the effects of aflatoxin (AF) on the exocrine pancreas in quails by means of light and electron microscopy. A total of 30 quails were divided into three groups, each composed of ten animals. Total AF was incorporated into the diet of these groups, at doses of 0, 2.5, and 5.0 mg of AF/kg feed, ppm, respectively. The quails were raised in cages with electrical heating and 24-h lighting for a period of 3 weeks. Ad libitum access was provided to feed and drinking water. Pancreas samples were taken for light and electron microscopic examination from animals that were killed by means of cervical dislocation at the end of the study. Light microscopic examination demonstrated mild mononuclear cell infiltration of exocrine tissue and vacuolisation of acinar cells in the group fed on AF at 2.5 ppm. On the other hand, electron microscopic examination demonstrated degranulation of the rough endoplasmic reticulum (rER) of acinar cells, decrease in the number of zymogen granules and free ribosomes and polisomes, and dilatation of capillaries in the group fed on AF at a dose of 2.5 ppm. Numerous degenerative acinar cells were determined in the group fed a diet containing 5.0 ppm AF, in addition to the findings common with the other group exposed to the toxin.Öğe The Histological Structure of the Exocrine Pancreas in Angora Rabbits(Kafkas Univ, Veteriner Fakultesi Dergisi, 2009) Şimşek, Nejdet; Ergün, Emel; Ergün, LeventIn this study, the exocrine pancreas of the Angora rabbits was examined by light and electron microscopical methods. Pancreas samples taken from rabbits were fixed in bouin and gluteraldehyde-paraformaldehyde Solutions. Then, these tissues processed by histological methods were embedded in araldite M and paraphlast. In the light and electron microscopic examination, the exocrine pancreas was constituted by acinar cell with small, moderate and large diameter- ducts. Pyramidal epithelial cells that compose the acini were demonstrated to be rich from rough endoplasmic reticulum, crystal type mitochondria, free ribosomes and high electron-dense zymogene granules. Moderate and large diameter- ducts were contained commonly prencipal cells, numerous goblet cells and a few enteroendocrine cells in lamina epithelialis, and mucous and sero-mucous glands in lamina propria. In conclusion, the histological structure of exocrine pancreas in Angora rabbits are similar in human, rat, mice, and cat, whereas are determined fairly different from mammalian species by caused containing goblet cells, mucous and sero-mucous glands in pancreatic ducts. These cells containing neutral, acidic and mix mucin might be Supported the secretion metabolism of the exocrine pancreas in the Angora rabbits.Öğe Immunohistochemical distribution of glucagon -, insulin -, somatostatin -, gastrin-, and serotonin-containing cells in the pancreas of the Van cat(2014) Karaca, Turan; Kara, Adem; Şimşek, Nejdet; Uslu, Sema; Tekiner, Deniz; Yörük, MecitThe 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 frst time. The immunopositivity and distribution of endocrine cells in the Van cat pancreas were determined to be partially diferent from those of other carnivorous species such as dogs and other cats.Öğe Morphological studies on ovarian mast cells in the cow(Scientific Technical Research Council Turkey-Tubitak, 2007) Özen, Asuman; Ergun, Levent; Ergun, Emel; Şimşek, NejdetThis study was conducted on cows in the estrual and luteal phases of the cycle to determine the staining properties, light and electron microscopic appearance and numerical distribution of mast cells from various areas of the ovary. The material for the study comprised ovarian specimen taken from 14 cows, 7 in the luteal phase and 7 in the estrual phase of the sexual cycle. Specimens were taken from 3 different areas of the ovaries, including those surrounding the corpus luteum, the graafian follicle and the medulla. From all 3 areas, mast cells were demonstrated as metachromatic staining after treatment of paraffin- embedded sections with toluidine blue and as Ab(+)/ SO(-) by the combined alcian blue/ safranine O (Ab/ SO) stain. In the electron microscopic studies, the mast cells were observed to have 2 types of granules, namely homogeneously dense granules and tiny particulate granules. All 3 regions of the ovary were observed to have higher average mast cell counts per mm 2 during the estrual phase than during the luteal phase (P < 0.001). In the estrual phase, while mast cell counts demonstrated a marked increase in the periphery of the graafian follicle, a low number of mast cells was determined in the periphery of the corpus luteum. In comparison, the medulla was demonstrated to have a much higher concentration of mast cells in the medulla than the other 2 regions of the ovarium.Öğe Ultrastructure of pancreatic alpha and beta cells in young quails (Coturnix coturnix japonica) fed aflatoxin(M H Schaper Gmbh Co Kg, 2007) Şimşek, Nejdet; Ergün, Levent; Ergün, E.; Alabay, B.; Özen, A.The present investigation was undertaken to assess the effects of aflatoxin (AF) containing diets on alpha and beta cells of the endocrine pancreas in young quails by means of light and electron microscopy. A total of thirty quails were divided into 3 groups, each comprising 10 animals. Total AF was incorporated into the diet of these groups, at dosages of 0 (control, group 1), 2.5 (group 2), and 5.0 (group 3) mg AF/kg feed. The chicks were housed in electrically heated battery cages and exposed to light for 24 h from hatching to 3 weeks of age. Quails consumed the diets and water ad libitum. Electron microscopic examinations demonstrated degranulation of alpha cells, decrease in the size and number of secreting granules, and increase in the number of free ribosomes and polisomes in the animals of group 2 and 3. In beta cells, the numbers of free ribosomes and polisomes decreased, whereas the number of mature granules increased in the animals of group 3. Mononuclear cell infiltrates were observed in the periphery of capillaries and around endocrine islets in the experimental groups. Furthermore, capillaries of the animals in group 2 and 3 were dilated at all sides of both alpha and beta islets. According to the results of this study, the addition of aflatoxin to the diets of quails at dosage of 2.5 and 5 mg AF/kg leads to significant changes in pancreatic alpha and beta cells. These changes may exhibit adverse effect on the metabolism of carbohydrates in poultry.
