Authors:N. Nagy, B. Igyártó, A. Magyar, Emese Gazdag, V. Palya, and I. Oláh
The oesophageal tonsil of the chicken is a novel member of the mucosal-associated lymphoid tissue (MALT), which is located around the entrance of the proventriculus. It consists of 6 to 8 single units, which are surrounded by a thin fibrous capsule. Each one is organised around the bottom of the longitudinal folds of the oesophagus, and serves as a 'tonsillar crypt'. Stratified squamous epithelium is infiltrated by lymphoid cells, i.e. T cells, plasma cells, macrophages, and dendritic cells, but not B cells, to form lymphoepithelium (LE). In the LE vimentin-, MHC II- and ATPase-positive cells possibly represent Langerhans' cells, but the appearance of 74.3 positive cells in the LE is unusual, because the 74.3 monoclonal antibody (mAb) recognises chicken follicular dendritic cells in the germinal centre and medulla of the bursal follicles. The subepithelial lymphoid tissue is organised into T- and B-dependent regions, which are the interfollicular areas and the germinal centres, respectively. Existence of high-endothelial venules in the interfollicular region suggests an extensive cellular connection between the oesophageal tonsil and the other lymphoid organs. In the resting oesophagus the lumen is closed, but during swallowing a bolus the crypt opens and the lymphoepithelium can be exposed to undigested food, antigens, infectious agents and vaccines. The location of the oesophageal tonsil, cranial to the stomach, may provide this organ with a unique role as compared to the other parts of the MALT; namely, it may contribute to the replication of infectious bursal disease virus (IBDV) and/or the pathogenesis of infectious bursal disease.
Authors:J Fodor, A Gomba-Tóth, T Oláh, E Zádor, Zs Cs Tóth, I Ioannis, B Molnár, I Kovács, and L Csernoch
Atherosclerosis is a disease caused by a build-up of fatty plaques and cholesterol in the arteries. The lumen of the vessels is obliterated resulting in restricted blood supply to tissues. In ischemic conditions, the cytosolic Ca2+ level of skeletal muscle may increase, indicating the alteration of Ca2+ removal mechanisms. Ca2+ is transported from cytosol into the sarcoplasmic reticulum by Ca2+ ATPase (SERCA), with its 1a isoform expressed in adult, while its 1b isoform in neonatal and regenerating fast-twitch skeletal muscle. To investigate the role of these isoforms in ischemic skeletal muscle, biopsies from musculus biceps femoris of patients who underwent amputation due to atherosclerosis were examined. Samples were removed from the visibly healthy and hypoxia-affected tissue. Significantly increased SERCA1a expression was detected under the ischemic conditions (246 ± 69%; p < 0.05) compared with the healthy tissue. Furthermore, the ratio of SERCA1a-positive fibers was slightly increased (46 ± 4% in healthy tissue and 60 ± 5% in ischemic tissue; p > 0.05), whereas SERCA2a did not change. In addition, in primary cultures derived from hypoxia-affected tissue, the diameter and fusion index of myotubes were significantly increased (30 ± 1.6 µm vs. 41 ± 2.4 µm and 31 ± 4% vs. 45 ± 3%; p < 0.05). We propose that the increased SERCA1a expression indicates the existence and location of compensating mechanisms in ischemic muscle.
Authors:J.T. Padra, I. Seres, A. Oláh, F. Fenyvesi, G. Paragh, G. Paragh, László Csernoch, G. Fóris, and P. Kertai
In our experiments we compared the serum lipoprotein lipid composition of Fischer 344 (F344) and Long-Evans (LE) inbred rats as well as of their hybrid FLF1 from both sexes after feeding them for 2, 4 and 8 weeks with different diets. The following diets were used: 1) standard diet marked as CRLT/N; 2) diet reach in butter marked as BR; 3) diet containing cholesterol, sodium cholate and methylthiouracil marked as CR; 4) diet marked as BRC, which is the Hartroft-Sós diet modified by our research group consisting of the diets BR and CR. The latter diet was the most effective, because within two weeks the level of serum total cholesterol, LDL-cholesterol, HDL-cholesterol and triglyceride in the F344 female rats increased 8, 30, 4 and 8 times, respectively. The male rats of the Long-Evans strain showed moderately increased values while the FLF1 female hybrids derived from the hybridization of LE males and F344 females had values closer to those of the mother strain. Despite the fact that during this time the LDL/HDL ratio increased from 0.06 to 2.97 and the PON-1 activity decreased to one-third, a significant lipid deposition could not be shown in the wall of the abdominal aorta even two months later. Our experimental model is suitable for the chemoprevention of dyslipidaemia or rapid testing of molecules chosen for its treatment.