Emel Ergün

Identification of intestinal M cells in isolated lymphoid follicles and Peyer's patches of the Angora rabbit

The presence, distribution, and localization of M cells in isolated lymphoid follicles (ILF) and in follicle-associated epithelia (FAE) covering Peyer’s patches (PP) in Angora rabbits were investigated by immunohistochemistry and electron microscopy. Although PP could macroscopically be identified along the length of the mucosal and serosal surfaces of jejunum and ileum, the presence of ILF could only be located microscopically. Typical M cells in FAE were detected within the periphery of the dome regions of the PP, and immature columnar M cells in the FAE resided in the vicinity of the crypts. M cells in the FAE of both ILF and PP showed vimentin-positive reaction. M cells in the FAE of ILF were morphologically similar to the immature M cells found in the FAE of PP. Typical mature M cells were also observed in the FAE of a few ILF. In contrast to FAE of PP, numerous goblet cells were observed in the FAE of many ILF. Moreover, among intestinal villi, we noticed villi-like solitary lymphoid structures that showed abundant lymphocytes in their lamina propria and that were surrounded with vimentin-positive cells and goblet cells. Thus, the occurrence of copious immature M cells and goblet cells, in addition to the detection of villi-like solitary lymphoid structures full of lymphocytes in the FAE of many ILF, indicate that ILF do not complete their immunological maturation in contrast to PP. Various antigenic stimulations conceivably induce the formation and maturation of ILF along the length of the small intestine. The morphological resemblance between ILF M cells and PP M cells suggests that these two types of cells perform similar or the same immunological functions.

Immunohistochemical Expression of Nitric Oxide Synthase Enzymes (iNOS, eNOS, nNOS) in the Estrual and Luteal Phases of the Sexual Cycle in the Cow Oviduct

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.

Köpek derisindeki mast hücreleri: dağılım, yoğunluk, heterojenite ve tespit tekniklerinin etkisi

This study was conducted with the aim of examining the location, the morphology, and numerical distribution of mast cells in the different areas of the healthy adult dog skin. Skin samples taken from the cheek, pinna, thorax and thigh areas of 10 healthy dogs were used as the study material. The results show the existence of mast cell heterogeneity in dog skin with respect to staining with alcian blue / safranin O and formaldehyde fixation sensitivity. Mast cells characterized by four combination of these parameters were observed: Mast cells containing only alcian blue-positive granules which were formalin-sensitive, mast cells containing only alcian blue-positive granules which were formalin-resistant, mast cells containing only safranin O-positive granules which were formalin resistant and mast cells containing a mixture of alcian blue-positive and safranin O-positive granules which were formalin resistant. With toluidine blue staining method, it was founded that IFAA fixed tissues were contained more mast cells than those tissues fixed with the 10% formaldehyde in all four regions. The difference in average number of mast cells per mm² between the IFAA and the 10% formaldehyde fixed tissues was statistically significant (p0.05), in the other three areas, statistically significant differences (p