The 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.

This study was aimed to determine staining intensity, cellular localization and distribution of the nitric oxide synthase (NOS) enzymes during the sexual cycle in the cow oviduct. Oviduct samples belonging to 20 cows, 10 of which were in the estrual phase and 10 in the luteal phase of the sexual cycle, were examined by an immunohistochemical procedure to determine the presence of the NOS enzymes. In the epithelial cells of the isthmus, endothelial NOS (eNOS) expression showed a strong positive reaction during the estrual phase and a weak positive reaction during the luteal phase in the endothelium and smooth muscle of the blood vessels found in the serosa and lamina propria. eNOS expression was not observed in the epithelium of either the ampulla or the fimbria in the two particular phases of the sexual cycle. The eNOS reactions observed in the blood vessel wall in these regions were stronger during the estrual phase. eNOS activity was not observed in the tunica muscularis in any of the regions of the oviduct. During the estrual phase, it was observed that inducible NOS expression showed a stronger positive reaction in the epithelium and muscle layer of the isthmus and ampulla and in the epithelium of the fimbria, compared to the luteal phase. Neuronal NOS immunoreactivity was observed in the epithelial cells of all oviduct regions and in the muscle layer of the isthmus and ampulla and did not display any significant difference between the estrual and luteal phases.

The thymus is a primary lymphoid organ that provides the microenvironment required for the development of T lymphocytes. Thymic epithelial cells (TECs) are among the most critical components in the thymic microenvironment supporting thymocyte selection and maturation. Apoptosis is primarily a physiologic process that plays a major role during the development of T lymphocytes. The first purpose of this study was to examine morphological changes in apoptotic thymocytes by transmission electron microscope in piglets. The second purpose was to reveal the morphological typology of TECs in piglets. Tissue samples of the thymus were taken from healthy Yorkshire race pigs of two different age groups (7 days and 1 month). Ultrastructurally, apoptotic lymphocytes showed similar morphologies, but they also had differences in distribution. In both groups a high density of apoptotic and proliferating thymocytes was found in the cortex. The rate of apoptotic thymocytes in the cortex and medulla increased with age, respectively. It was observed that the TECs had various morphological subtypes in both the cortex and the medulla. A similar cellular distribution pattern of TECs was seen in both groups. It was concluded that the morphological diversity in the TECs may be related to the form-function relationship and the metabolic process.

Özet: Bu araştırmada, ratlarda gebeliğin değişik dönemlerinde plasentada bulunan trofoblastlar ve plasentaya ait diğer yapıların (desidua hücreleri, dev hücreler, glikojen hücreleri) histokimyasal ve immunohistokimyasal olarak incelenmesi amaçlandı. Materyal olarak gebeliğin değişik dönemlerinde bulunan, erişkin ve sağlıklı 20 adet rat kullanıldı. Histokimyasal olarak yapılan incelemeler sonucunda, gebeliğin ilk yarımında sitotrofoblastlar ve dev hücrelerinde kuvvetli PAS (+), sinsisyotrofoblastlarda ise kuvvetli AB (+) reaksiyon gözlendi. Gebeliğin ikinci yarımında görülen glikojen hücrelerinde mor renkli granüller halinde PAS/AB (+) boyanma gözlenirken, küçük bazofilik hücreler gittikçe artan miktarda AB (+) reaksiyon gösterdiler. Gebeliğin ilerleyen dönemlerinde vakuollü yapı gösteren desidua hücrelerinde de artan miktarda PAS (+) reaksiyon saptandı. İmmunohistokimyasal incelemelerde, trofoblast ve dev hücrelerinde implantasyonun olmasından gebeliğin sonuna kadar, hormonal aktivite oldukça fazla görüldü. Östrogen ve progesteron hormonlarına ait reseptörler hücrelerin sitoplazma ve çekirdeklerinde yoğun olarak bulunuyordu. Gebeliğin sonuna doğru progesteron reseptörlerinde azalmanın olduğu, fakat gebeliğin her döneminde iki hormona ait reseptörlerde, reaksiyon şiddetinin fazla olduğu dikkati çekti.Abstract: In this study, it was aimed to examine trophoblast cells and other placental structures (decidua cells, giant cell, glycogen cell) histochemically and immunohistochemically in various periods of gestation in rats. Twenty adult, healty and pregnant rats were used as materials. By histochemical examinations it was observed that there were significant AB (+) reactions in syncytiotrophoblasts, PAS (+) reactions in giant cells and cytotrophoblasts in the first half of gestation. In the second half of gestation, glycogen cells were stained with PAS/AB (+) in purple coloured granules and small basophilic cells showed gradually increasing AB (+) reactions. In the advanced state of gestations, decidual cells having vacuoles showed increasing PAS (+) reactions. In immunohistochemical examinations, hormonal activities increased significantly in trophoblasts and giant cells during the period staining from the implantation to the end of gestation. Oestrogen and progesterone receptors were found in high density in the cytoplasm and nucleus of the cells. Progesterone receptors decreased slightly towards the end of pregnancy, however, reactions were high in receptors belonging to both hormones in every period of pregnancy.

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