Enzyme-linked immunosorbent assays (ELISAs) were developed to measure IgE antibodies specific for Dermatophagoides farinae in dogs and cats. Although higher levels were detected in atopic dogs and cats than in normal animals without skin disease, the differences were not statistically significant. On the other hand, levels in dogs and cats that were reared under laboratory conditions, and thus presumably not exposed to house dust mites, were either very low or undetectable. IgE antibodies were induced in 10 laboratory-reared cats using low-dose antigenic stimulation in aluminium hydroxide. All cats developed detectable IgE, but not all developed positive skin tests. However, serum from those cats with positive skin tests were able to give positive Prausnitz–Küstner (PK) tests. The canine data, together with previous work on basophil histamine release, suggests that the distinction between atopic and normal dogs may result from a heterogeneity of either IgE or of the high-affinity mast cell receptor. The feline data can only be explained by the existence of a heterogeneity of IgE. 相似文献
Previous studies have indicated that when Atlantic salmon, Salmo salar L., are exposed to Neoparamoeba sp. the fish produce anti-Neoparamoeba sp. antibodies. It appears unlikely that these antibodies elicit any specific protection against amoebic gill disease (AGD) as fish with demonstrable activities have been affected by AGD. Experiments were conducted on Atlantic salmon cultured throughout Tasmania to assess the natural production of antibodies towards Neoparamoeba sp. Fish were sampled from areas where AGD was prevalent and from areas where there had been no reported cases. An enzyme-linked immunosorbent assay (ELISA) was used to measure anti-Neoparamoeba sp. antibody activities in serum. All fish from sea water had antibody activities greater than the negative control fish, including fish from areas with no reported cases of AGD. Time trial samples indicated that time after transfer to sea water did not appear to be a significant (P > 0.05) factor in antibody activity, however location was (P < 0.05). There was no agreement (corrected kappa value, 0.16) between the ELISA result and the isolation of Neoparamoeba sp. from the gills of the same fish. The results suggest that Atlantic salmon in seawater culture in Tasmania produce anti-Neoparamoeba sp. antibodies regardless of infection history, suggesting the presence of Neoparamoeba sp. in the environment. 相似文献
Serum and mucosal antibody responses of juvenile rainbow trout, Oncorhynchus mykiss, were characterized by enzyme‐linked immunosorbent assay (ELISA) following immunization with various preparations of formalin‐killed Flavobacterium psychrophilum cells. The protective nature of these preparations was then determined by immunizing rainbow trout fry and challenging with the bacterium. Juvenile rainbow trout immunized intraperitoneally (i.p.) with formalin‐killed F. psychrophilum emulsified with Freund's complete adjuvant (FCA), and i.p. with formalin‐killed F. psychrophilum either with or without culture supernatant generated significant serum antibody responses by 6 and 9 weeks, respectively. Significant mucosal antibody responses were detected by 9 weeks only in fish immunized i.p. with killed F. psychrophilum/FCA. Following immunization and bacterial challenge of rainbow trout fry, protective immunity was conferred in F. psychrophilum/FCA and saline/FCA groups with relative per cent survival values of up to 83 and 51, respectively. Significant protection was not observed in treatment groups immunized by immersion or i.p. without adjuvant at the challenge doses tested. Results suggest that stimulation of non‐specific immune factors enhances the ability of fish to mount a protective immune response, but specific antibody appears necessary to provide near complete protection. In this study, an ELISA was developed to monitor anti‐F. psychrophilum antibody production in trout. The relationship of such responses to protective immunity suggests that future vaccination strategies against coldwater disease may require stimulation of both the innate and adaptive arms of the immune response. 相似文献
Identification of new parental lines is crucial for developing ecology‐specific hybrids with ideal agronomic performance. We screened a total of 570 different ecology‐specific Indian rice varieties for the presence of fertility restorer genes, Rf3 and Rf4 using tightly linked markers DRRM Rf3‐10 and RM6100, respectively. Among these varieties, 13% carried Rf3Rf3/Rf4Rf4, 31% carried rf3rf3/rf4rf4, 6% carried Rf3Rf3/rf4rf4 and remaining 50% carried Rf4Rf4/rf3rf3 allelic combinations. A mini set of 40 varieties with variable allelic combinations of fertility restorer genes were testcrossed with WA and Kalinga‐based CMS lines. All the 80 F1s were evaluated for spikelet fertility and fertility restoration ability. Rf3Rf3/rf4rf4 genotypes mostly behaved as partial maintainers or partial restorers. In contrast, rf3rf3/Rf4Rf4 genotypes were partial or effective restorers. However, double dominant genotypes showed better fertility restoration than the genotypes containing Rf3 or Rf4 individually. Some of the genotypes showed unexpected restoration pattern implying occurrence of other fertility restorer(s) apart from Rf3 and Rf4. The perfect restorers and maintainers identified in this study can be directly used in hybrid rice breeding. 相似文献
Objective Guinea pigs have a very low threshold of corneal sensitivity and at the same time nearly no reflex tearing compared to dogs, cats, and horses. The question arose whether there is a general correlation between corneal sensitivity and the quantity of reflex tearing. Animals studied Totally 160 animals of 8 different species (20 animals per species) were investigated. Procedures The corneal touch threshold (CTT) was measured with a Cochet–Bonnet esthesiometer. The palpebral fissure length (PFL) was measured with a calliper ruler. The Schirmer tear test (STT) was modified by adapting the width of the STT strip to the PFL of every species. For the STT II, 0.4% oxybuprocaine was applied. Results Corneal touch threshold: Cows (1.67 g/mm2), horses (1.23 g/mm2), sheep (1.13 g/mm2), goats (1.44 g/mm2), dogs (2.16 g/mm2), and cats (1.33 g/mm2) show similar CTT values. In contrast, rabbits (6.21 g/mm2) and guinea pigs (7.75 g/mm2) show a significantly lower CTT. Tear Production Difference STT I ? STT II: Rabbits have the greatest decline in tear production with 38.4%, followed by sheep (33.3%), dogs (31.1%), cats (24.7%), cows (23.7%), horses (18.0%), and goats (14.0%). Guinea pigs have no decline, but a slight increase of ?16.0%. Correlation CTT and STT II ? STT I Difference: Pearson’s correlation coefficient shows a small, but significant correlation. The coefficient of determination can only forecast a value with 7.1% certainty. Conclusions The high variance and low reproducibility of results suggest that the measuring devices are inappropriate to assess the evaluated parameters. Therefore, no assured correlation between the corneal sensitivity and the quantity of reflex tearing could be found. 相似文献
Serological investigations focused on the detection of specific opisthorchiid liver fluke antibodies in silver foxes (Vulpes vulpes fulva). Animals were experimentally infected with Opisthorchis felineus (nos. 1 and 2) and Metorchis bilis (nos. 3–8) by feeding fish with a counted number of metacercariae. Four foxes remained as non-infected negative controls (nos. 9–12). For the indirect ELISA, an excretory–secretory antigen was produced by in vitro cultivation of O. felineus and M. bilis adults isolated from livers of experimentally infected hamsters.
Immunoglobulin G (IgG) seroconversion against homologous antigen took place between weeks 2 and 6 postinfection (p.i.) and foxes remained seropositive up to the end of the trial at week 41 p.i. In contrast, IgG titres against heterologous antigen remained significantly lower and stayed near the cut-off. All infected animals excreted opisthorchiid eggs, starting between weeks 2 and 4 p.i. The number of liver flukes found at necropsy was relatively low, except in one fox that was sacrificed at the week 11 p.i. These results suggest that the ELISA is a suitable tool for the detection of specific O. felineus and M. bilis antibodies in the fox. 相似文献