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Avian adenoviruses (Aviadenovirus) belong to three groups. Group I contains five aviadenovirus species (A-E) with twelve serotypes isolated from fowls as well as duck adenovirus, pigeon adenovirus and turkey adenovirus. Group I of aviadenovirus plays no major role in mixed infections, although FadV-4 strains cause a dangerous disease in chickens - hydropericardium-hepatitis syndrome. Group II of the aviadenovirus includes the hemorrhagic enteritis virus of turkeys, marble spleen disease virus of pheasants and the splenomegaly adenovirus of chickens. In fact, the adenoviruses of this group are included in the Siadenovirus genus because the techniques of molecular hybridizations and DNA sequencing have indicated that there is a gene coding for sialidaze in their genome. The egg drop syndrome virus however, belongs to group III. Atadenovirus has been proposed as a name for this group of aviadenoviruses as it reflects the high adenine-thymidine (AT) content in their genome. The significance of adenovirus in pathology within poultry is constantly increasing.
The aim of the study was to compare the effectiveness of calves infected with bovine leukaemia virus with that gained after the administration of FLK-BLV cells and lymphocytes of a leukaemic cow. The experiment was carried out on two groups of animals aged from 6 to 8 months. Each group of the cows was infected intravenously with the same dose of 1.2 x 105 FLK cells or lymphocytes. The third group involving two animals served as the control one. The sera of calves were tested at 2, 4, 6 weeks and 2, 3, 4 and 5 months after infection. The geometric mean titer of FLK infected calves was 3.9; 50.8; 101.6; 80.0; 64.0; 63.5 and 51.2 and in the group infected with lymphocytes - 0.0.; 511.6; 776.0; 2051.0; 1559.0; and 504.1, respectively. Serological examinations by means of the ELISA test revealed specific antibodies at two weeks after infection in the FLK group and at four weeks in the lymphocyte treated group. The highest titers were observed at six weeks in the sera of calves of the first group and at two months in case of the second group. It was found that the highest titer of antibodeis in the calves infected with lymphocytes was 20-fold higher than that of FLK cells infected animals.
Pestiviruses cause serious diseases in domestic and wild ruminants and swine. The aim of the study was to apply Real Time PCR with SYBR Green I intercalating dye for detecting pestiviruses. The study was performed with RNA extracted from BVDV-1 cell culture and CSFV, DNA templates with known copy numbers synthesized from CSFV, BVDV-1 and BDV and on cDNA samples representing different pestivirus species and strains. Two PCR kits were used in the study: AmpliTaq Gold (Applied Biosystems) with added fluorescent dyes, and QuantiTect SYBR Green PCR kits (Qiagen). PCR primers were selected from 5UTR. All pestivirus species, or species-related samples were detected using the applied method and the results were observed as amplification curves. The specificity of amplification was confirmed by estimating the melting temperature of the PCR products. It was demonstrated that the melting temperature of amplicons obtained in reaction with QuantiTect kit was 86-87°C while those obtained with AmpliTaq Gold was 90-92°C. A higher assay sensitivity of 40 copies of CSFV, 400 copies of BVDV and 40 000 copies of BDV templates was obtained using the QuantiTect SYBR Green PCR kit. It should be stressed that the above method does not facilitate pestivirus species identification and may only be a preliminary method for detecting pestivirus infections in swine and must be supplemented with CSFV specific assay.
The purpose of the survey was to assess the prevalence of BHV-1, PI-3, BHV-4, BRSV and BVD in the bovine respiratory tract. Sera were taken from cattle of four districts located in the south-western part of Poland: 349 sera were collected from cows, 183 from heifers and 27 from bulls with no clinical signs of the disease. The findings revealed higher indices of infection caused by the viruses in the group of cows as compared with the one of heifers, and the highest percentage of infections due to PI-3 virus in all groups of the animals. With respect to viruses and districts under study, the following indices of infections were found: BHV-1 from 6.2 to 44.4 per cent, PI-3 from 32.7 do 69 per cent, BHV-4 from 13.9 to 40 per cent, BRSV from 8.5 to 44.4 per cent and BVD from 8.5 to 27.7 per cent. The results indicate significant differences in respect to virus infections caused mainly by the home and international market of cattle. It is worth mentioning that mixed infections were observed more often than monoinfections.
Reverse transcription coupled with the polymerase chain reaction (RT-PCR) was used for the detection of HCV and BVDV in virus cell cultures. Reverse transcription reaction was performed with RNA isolated by means of the guanidine method or with cell culture supernatant precipitates by eliminating the RNA isolation step. Both reactions, RT and PCR, were carried out by using rTth DNA polymerase in one tube. The RT-PCR products were analysed by a gel electrophoresis and hybridization with the digoxygenine labelled DNA probe. It was demonstrated that it is possible to omit the RNA isolation step and that applied primers are suitable for diagnosing HCV and BVDV.
The study was carried out in 13 Polish Primitive Horses.Ten of them were subjected to stress and infected with equine influenza virus (the mixture of subtype A-equi/1 and A-equi/2). Three horses were left as controls. The coagulation time by Lee and White method and caolin-kephalin and prothrombin times in plasma citrate were determined with a coagulometer. Concentration of fibrinogen (Quick method) and platelet count (procaine method) were determined as well. The means of the above parameters before and after infection in relation to the values in control animals were compared. The results of the experiment show that the caolin-kephalin and prothrombin times have been shortened in infected horses, the platelet count has been decreased and the concentration of fibrinogen has been increased. The changes in the coagulation system were statistically significant. Thus the results of the experiment have confirmed the hypothesis that in the course of influenza infection disturbances in the coagulation system may occur.
Tetraspanins are a superfamily of surface membrane proteins characterized by their four transmembrane domains. They associate laterally with their partner proteins or with each other, and form large integrated signaling complexes or tetraspanin enriched microdomains (TEMs). Consequently, those proteins are involved in the coordination of many biological processes, including cell adhesion, migration and proliferation. Tetraspanins also play a prominent role in the pathogenesis of viral infectious diseases. Viruses can exploit tetraspanins for the modulation of the host immune response and/or for subsequent immune evasion. Thus tetraspanins are attractive novel antiviral therapeutic targets, which may provides a novel strategy to inhibit critical processes of viral infection. This review summarizes the involvement of tetraspanins in viral life cycles, including adsorption, entry, viral trafficking, fusion events and viral release.
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