Simultaneous detection of vaccinal and field infectious bursal disease viruses in layer chickens challenged with a very virulent strain after vaccination.

Infectious bursal disease virus is an important poultry pathogen. It is distributed worldwide and causes significant economic losses. In this study, a system was adopted for the simultaneous monitoring of vaccine and virulent strains using reverse transcription polymerase chain reaction (RT-PCR). After the decay of maternal antibodies, chickens were vaccinated at the age of 37 days with a virus of intermediate virulence and challenged at 5, 10 and 14 days post vaccination (dpv). The challenge was done with IBDV strain CH/99. Sequencing of the hypervariable region of VP2 has shown that CH/99 belongs to the very virulent group of viruses. The vaccine virus could be found in the bursa of Fabricius, spleen, thymus and bone marrow until 24 dpv. The CH/99 challenge virus was found in the bursa and lymphoid organs when chickens were challenged at 5 and 10 dpv. When challenge was performed at 14 dpv, the pathogenic virus could not be found in the bursa and other lymphoid organs.

The effects of chronic stress on thymus innervation in the adult rat.

Various stressors induce changes in the immune system. However, it has not yet been analyzed how stressors affect thymus innervation. To examine whether chronic stress alters the morphology of the thymus by changing the nerve components of the thymus, adult male rats, 9-weeks old, were exposed to forced swimming during 21 successive days. The animals were sacrificed by decapitation after the last session and their thymuses were used for analysis of (i) the thymus compartments, (ii) distribution patterns of monoamine-containing nerve profiles and (iii) distribution patterns of acetylcholinesterase (AChE)-containing nerve profiles. Our results show that chronic stress in rats reduces the volume of both thymus cortex and medulla, numbers of thymocytes in the deep cortex and medulla and the density of fluorescent nerve profiles, whereas it increases density of fluorescent cells. The distribution patterns of nerve profiles containing monoamine and AChE were not affected. These changes indicate that chronic stress affects thymus development and T cell maturation by altering the sympathetic nerve component.

[Detection of Helicobacter pylori in gastric biopsy and resection specimens]. / Otkrivanje Helicobactera pylori u uzorcima dobijenim biopsijom i resekcijom zeluca.

AIM: To compare the sensitivity of detecting H. pylori in gastric biopsy and resection specimens using modified Giemsa stain and immunohistochemistry, using a commercially available anti-H. pylori antibody (Dako, Denmark). METHODS: Gastric antral biopsy specimens showing chronic gastritis (28 cases) together with tissue blocks from gastrectomy specimens for duodenal ulcer (2 cases) were stained with modified Giemsa and immunoenzymatic alkaline phosphatase - anti-alkaline phosphatase (APAAP) method, and were carefully examined for the presence of H. pylori. RESULTS: Using a modified Giemsa stain, the spiral shaped bacteria of H. pylori stained blue, were attached to the brush border of the gastric foveolar epithelial cells. However, the specificity of modified Giemsa stain depended on the morphological appearance of H. pylori. The specificity of immunostaining permitted detection of low numbers or even single organisms. In all cases bacteria were more prominent and easier to detect in immunostained preparations. H. pylori was identified in 22 (73.3%) of 30 sections stained with modified Giemsa stain, but it could be identified with greater frequency in sections stained with APAAP, in 27 (90%) of 30 sections. CONCLUSION: Immunohistochemical identification of H. pylori was better than Giemsa stain for detecting that organism.