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151.
Bulk-tank milk samples analysed in a Bovine Herpesvirus-1 (BHV-1) blocking ELISA are still in use in the Danish BHV-1 programme as a tool to classify dairy herds as BHV-1 infected or BHV-1 free herds. In this retrospective study, we used data from the Danish BHV-1 eradication campaign to evaluate performance characteristics of the BHV-1 blocking ELISA in 1039 BHV-1-seropositive and 502 repeatedly BHV-1-negative dairy herds using the results of blood testing of the individual animals as the true infection status. At a cut-off value of 30% blocking reaction, the herd-level relative sensitivity and relative specificity were 82 and 100%, respectively. The herd-level relative sensitivity depended on the within-herd prevalence of seropositive cows and the cut-off value in the assay, but not on the time interval (up to 90 days) between the collection of the bulk-tank milk sample and the individual serum samples. The BHV-1 blocking ELISA on bulk-tank milk could detect seropositive herds (few), with prevalence proportions as low as one seropositive cow out of 70 cows. 相似文献
152.
H Li T C McGuire U U Müller-Doblies T B Crawford 《Journal of veterinary diagnostic investigation》2001,13(4):361-364
An earlier competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA) was developed for detection of specific antibody against malignant catarrhal fever (MCF) viruses (MCFV) in ruminants. In this study, the indirect CI-ELISA was improved by conjugating the monoclonal antibody 15-A directly with horseradish peroxidase and by developing a method of producing precoated, dried antigen plates. This new test is referred to as a direct CI-ELISA. The reformatted test yielded a significantly improved sensitivity, and the time required was reduced to about one-sixth of the previous time. Of 37 MCF cases in cattle that were confirmed by histopathology and polymerase chain reaction (PCR) assay, 37 (100%) were positive by the new test, whereas the indirect CI-ELISA detected only 23 (62%). The direct CI-ELISA detected antibody to MCFV in 100% of 48 sheep that had been defined as infected with ovine herpesvirus 2 (OvHV-2) by PCR, whereas the indirect CI-ELISA detected only 41 (85%). Comparison of antibody titers measured by the 2 assays for sera collected from OvHV-2-infected sheep and from cattle, bison, and deer with clinical sheep-associated MCF revealed that the direct CI-ELISA offered a 4-fold increase in analytical sensitivity over the indirect format. The number of seropositive animals detected by the direct CI-ELISA among apparently normal cattle and bison was 2-3 times greater than the number detected by the indirect CI-ELISA, indicating that a significant percentage of normal cattle and bison are subclincally infected with MCFV. 相似文献
153.
The mean percentage of cells forming rosettes with 2-aminoethyl isothiouronium bromide-treated sheep erythrocytes (EAETRFC) in the peripheral blood of 10 horn cancer-affected cattle (40.05 +/- 2.91) was significantly low in comparison to the value in unaffected control animals (58.61 +/- 1.68). Immunotherapy with a saline phenol extract of allogeneic tumour tissue resulted in a gradual increase in the mean percentage of EAETRFC on each subsequent week. The increase was statistically significant from the second week onwards and on the sixth week, the percentage of EAETRFC in horn cancer affected cattle (56.80 +/- 1.38) closely approximated the value in unaffected controls. 相似文献
154.
U. R. Sangakkara 《Journal of Agronomy and Crop Science》1995,175(1):51-56
Cardamom is a popular and important tropical spice, traditionally propagated by rhizomes, although seeds which are considered recalcitrant are being increasingly used in planting programmes. Thus a study evaluated the effects of pod maturity on pod, seed and germination characteristics of three popular varieties, along with the influence of drying on seed germinability.
Green and yellow mature pods and seeds of all varieties had a high moisture content. The variety Mysore, which is considered high yielding, had larger pods with a greater number of heavy seeds. Although the pods of Vazukka were heavier than the Malabar variety due to greater seed weights, seed numbers were similar in both varieties. Seed moisture contents declined with increasing pod maturity, while seed weights and germinability increased.
The germinability of Mysore seeds were greater, while that of the other varieties were lower. The larger seeds of all varieties germinated 15–20 days earlier, giving rise to a greater percentage (20–25 %) of seedlings. Desiccation at 20 °C maintained germinability for a longer period (5–9 days) in all varieties, than when dried at 30 °C. The seeds of the variety Mysore was more tolerant to desiccation than other varieties. The study illustrated the importance of selecting large seeds from yellow mature pods of cardamom for propagation and the value of establishment immediately after harvest to obtain a greater number of seedlings. 相似文献
Green and yellow mature pods and seeds of all varieties had a high moisture content. The variety Mysore, which is considered high yielding, had larger pods with a greater number of heavy seeds. Although the pods of Vazukka were heavier than the Malabar variety due to greater seed weights, seed numbers were similar in both varieties. Seed moisture contents declined with increasing pod maturity, while seed weights and germinability increased.
The germinability of Mysore seeds were greater, while that of the other varieties were lower. The larger seeds of all varieties germinated 15–20 days earlier, giving rise to a greater percentage (20–25 %) of seedlings. Desiccation at 20 °C maintained germinability for a longer period (5–9 days) in all varieties, than when dried at 30 °C. The seeds of the variety Mysore was more tolerant to desiccation than other varieties. The study illustrated the importance of selecting large seeds from yellow mature pods of cardamom for propagation and the value of establishment immediately after harvest to obtain a greater number of seedlings. 相似文献
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