U. Eren

Effects of formaldehyde and xylene on CD4- and CD8-positive T cells in bronchus-associated lymphoid tissue in rats

The aim of this study was to determine the localization and number of CD4- and CD8-positive T lymphocytes in bronchus-associated lymphoid tissue (BALT) of the embryos and newborns or young and adult rats exposed to formaldehyde (6 ppm), technical xylene (300 ppm), or a combination of these two agents (3 ppm + 150 ppm) for 6 weeks (8 h/day). A total of 96 female Sprague-Dawley rats were used. The CD4-positive cells were localized predominately in area under the epithelium and in the periphery of BALT follicles after the exposure period. However, CD8-positive cells were localized mainly in the periphery of BALT follicles after the exposure period. The number of CD4- and CD8-positive lymphocytes significantly increased in exposed young and adult rats compared to the respective controls. These results suggest that formaldehyde and/or xylene may affect the local immunity in BALT particularly in young and adult rats.

A Histochemical Investigation of Different Distribution of TSH Cells in Adenohypophsis of Female and Male Rats

The aim of the present study was to investigate histochemically the localization of thyroid‐stimulating hormone (TSH) cells and the number of TSH cells in adenohypophysis of ovariectomized adult females, intact females at estrous and diestrous phase of sexual cycles and castrated and non‐castrated adult male rats. TSH cells, distributed throughout the pars distalis in all groups, were observed more frequent in areas near to the pars intermedia than other regions. The cells were round, ovoid, stellar‐shaped and had contacts with sinusoids. Their nuclei were large and round‐shaped. The cells were found mostly single or occasionally in groups of double and triple. The number of TSH cells was higher in estrous than diestrous phase in intact rats. In adenohypophysis of ovariectomized rats, their numbers were less than that of intacts in estrous, but higher than that of found in diestrous phases. Furthermore, the numbers of TSH cells in intact females during estrous phase was higher than those found in intact and castrated male rats. On the other hand, castration reduced the number of TSH cells while ovariectomy had no effect in this respect.

MHC class II expression by mast cells in the genital tract of cows

This work examined the presence of MHC class II molecules expressing mast cells in oviduct, uterus and vaginal tissues in cows. The tissue samples of five cows were collected from a local slaughterhouse. Toluidine blue pH 0.5 (TB) and avidin-biotin peroxidase complex (ABC) staining procedures applied to adjacent sections from tissue samples. It was determined that some TB + cells were also gave positive reaction with strept ABC staining for MHC II molecules. To our knowledge this is the first evidence indicating the presence of MHC class II molecules expressing mast cells in the cow.

MHC Class II+ (HLA‐DP‐like) Cells in the Cow Reproductive Tract: II. Immunolocalization of MHC Class II+ Cells in Oviduct and Vagina

The aim of this study was to determine and examine the distribution of major frequency MHC II+ cells in the oviduct and vagina of cows during the oestrous and dioestrus phases. Right oviduct (ampulla, isthmus) and vaginal samples taken from a total of twenty seven multiparous cows were used. Tissue samples were processed to obtain both cryostat and paraffin sections. Sections were stained immunocytochemically using StreptABC method using a specific monoclonal antibody to MHC II+ cell population. Intra‐epithelial and subepithelial areas along with lamina propria, muscularis mucosae and serosa of both ampulla and isthmus and intra‐epithelial/subepithelial areas and mucosae of vagina were examined for the presence of MHC II+ cells. The density of immune positive cells was determined using a subjective scoring system. MHC II+ cells were demonstrated in all areas examined in both oestrus and dioestrus. In oestrus, the density of MHC II+ cells decreased in subepithelial areas (in between the epithelial cells and the basal membrane) of isthmus, whereas the density of immune positive cells was increased in muscularis mucosae of isthmus (Pu2003<u20030.05), lamina propria and muscularis mucosae of ampulla (Pu2003<u20030.05) as well as in the mucosae of vagina (Pu2003≤u20030.005). This study indicates that the density of MHC II+ cells observed in the oviduct and vagina increases in the majority of areas examined due to the effect of oestrogen.

The several elements of intestinal innate immune system at the beginning of the life of broiler chicks

Functional capacity of digestive system and intestinal adaptive immunity are immature at hatching of broiler chicks. Therefore, intestinal innate immunity after hatching is vital to young chicks. The purpose of this study was to investigate expression and tissue distributions of several elements of the innate immune system (i.e., TLR2, TLR4, CD83, and MHC class II expressing cells) in the intestine of one‐day‐old chicks. For this purpose, ileum and cecum were examined the under different conditions, which included the control and 1, 3, 6, 12, or 24 h after injection of lipopolysaccharide (LPS) and phosphate buffered saline. The findings indicated that regardless of the antigenic stimulation, Toll‐like receptor (TLR) 2 and TLR4 expressing cells were present in the intestinal tissues of one‐day‐old chicks. We noticed that the intestinal segments have different TLR expression levels after LPS stimulation. Dendritic cells were identified, and they left the intestinal tissue after LPS treatment. MHC class II molecules were diffusely present in both the ileum and cecum. This study demonstrates that the intestinal tissue of one‐day‐old chicks has remarkable defensive material, including histological properties and several elements of the innate immune system. Microsc. Res. Tech. 79:604–614, 2016.