[Testosterone production after in vitro stimulation of testicular cells with gonadotropins in bulls]. / Produkce testosteronu po stimulaci varletních bunek býku gonadotropinem in vitro.

The response of bulls' testicular cells to the stimulation by serum gonadotropin ad us. vet. (Bioveta, Ivanovice in Haná) was investigated in in vitro tests. The testicular tissue was sliced, collagenase-split and the loosened cells were stimulated by gonadotropin concentrations of 7.8 to 250 I U per l; control samples without gonadotropin treatment were used for comparisons. The testicular cells responded to the increasing stimulation by higher production of testosterone.

Effects of oral intake of nitrates on reproductive functions of bulls.

Effects of oral intake of nitrates on selected biochemical and endocrinological indices and its impact on reproductive functions were investigated in five feeder bulls aged 16-18 months. The bulls were tested prior to (30 days), during (30 days) and after (35 days) the period of the nitrate administration. The initial dose of 100 g potassium nitrate per day was increased at weekly intervals by 50 g up to 250 g per day. The administration of nitrates resulted in a highly significant (P < 0.01) increase in methaemoglobin concentration and a non-significant decrease in the concentration of beta-carotene and a highly significant (P < 0.01) decrease in the concentration of E vitamin in blood serum. A significant (P < 0.01) increase in blood serum concentration of bile acids and prolonged biological half-life of progesterone were suggestive of an impairment of liver metabolism. Prolonged intake of excessive doses of nitrates resulted in a significant (P < 0.05) increase in cortisol concentration during and after the administration period, while depressed thyroid gland activity was evident from a significant (P < 0.05) decrease in thyroxin concentration during the administration period. A suppression of hypothalamic functions after the administration period was documented by non-detectable levels (< 0.001 microgram/ml) of thyrotropin in TRH test. Depressive effects of nitrates on the function of Leydig cells during and particularly after the administration period were apparent from weakening testicular responses to a treatment with GnRH. Biochemical analyses of seminal plasma revealed a highly significant (P < 0.01) increase in total acid phosphatase activity and a significant (P < 0.05) decrease in the concentration of fructose. No other significant changes in seminal plasma components were observed. Adverse effects of excessive intake of nitrates were also evident from reduced sperm motility in the 120-min thermal test. While no difference was found in the frequency of primary morphological abnormalities, the number of secondary abnormalities rose by 115% in the post-administration period and was suggestive of damaged membrane integrity. Histological examinations revealed degenerative lesions in cells of the spermiocyte and spermatid layers.

Detection and genetic characterisation of Hepatitis E virus in Czech pig production herds.

The objective of the present study was to carry out a small surveillance programme in Czech pig production herds using the nested reverse transcriptase-polymerase chain reaction (nRT-PCR) technique to trace Hepatitis E virus (HEV) in different biological samples and to characterise the detected swine HEV isolates by phylogenetic analysis. A total of 32 piglets from 11 herds clinically suspected of postweaning multisystemic wasting syndrome (PMWS) were examined. Bile, liver tissue and serum samples were collected from each animal. Due to the high genetic variability of HEV, three sets of primers targeting each of the open reading frames (ORFs) of its genome were used. HEV RNA was most frequently detected in the bile samples (40.0%), followed by liver tissue (16.1%) and serum (3.2%). Seven (63.6%) of the 11 monitored farms were found to have at least one HEV RNA positive piglet. Specific 242 bp sequences within the ORF1 coding non-structural proteins were sequenced and phylogenetically analysed. Phylogenetic analysis using the neighbor-joining and maximum parsimony method confirmed that all detected Czech swine HEV isolates belonged to genotype III. Comparison of the Czech swine HEV isolates with corresponding sequences of swHEV available in GenBank failed to find any 100% homologous HEV isolate.

Determination of some immunologic parameters in capillary blood samples.

A technique for the collection of capillary blood samples and their subsequent analysis is described. The procedure is especially intended for use in children, stomatologic patients and individuals under load test who are to be screened for the level of immunoglobulins. The applicability of this method was verified in a group of 71 patients treated for various chronic liver lesions at the Research Institute of Balneology. The aim was to avoid the distress of repeated venous blood samplings to patients who had to be examined for the dynamic of changes in their immunologic parameters. Totally, nine immunologic parameters were simultaneously determined in the capillary and venous blood of these patients. As confirmed by statistical processing of the data (t-test, F-test, correlation coefficients and regression line equations were calculated) both methods proved equally suitable in terms of the results yielded so that either of them can be safely used for routine human serum analyses. However, the use of the capillary blood technique turned out to cause less discomfort to the patients, and appears to be distinctly of advantage in children and stomatologic patients as well as in repeated blood samplings during load tests and examinations in animal experiments.

Atypical myxomatosis--virus isolation, experimental infection of rabbits and restriction endonuclease analysis of the isolate.

Atypical form of myxomatosis, which caused non-lethal and clinically mild disease in domestic rabbits 1 month after immunization with a commercially available vaccine MXT, is described. The isolated myxoma virus designated as Litovel 2 (Li-2) did not induce systemic disease following subcutaneous and intradermal applications in susceptible experimental rabbits but led to the immune response demonstrated by ELISA. No severe disease was induced in those Li-2 inoculated rabbits by challenge with the virulent strains Lausanne (Lu) or Sanar (SA), while the control animals showed nodular form of myxomatosis with lethal course of the illness. Restriction fragment length polymorphism (RFLP) of genomic DNA with KpnI and BamHI endonucleases was used for genetic characterization of the Li-2 isolate, the vaccine strain MXT and both virulent strains Lu and SA, respectively. In general, RFLP analysis has shown to be informative for inferring genetic relatedness between myxoma viruses. Based on restriction endonuclease DNA fragment size distribution, it was evident that the pathogenic strain SA is genetically related to the reference strain Lu and the isolate Li-2 is more related, but not identical, to the vaccination strain MXT.