A labeled avidin-biotin enzyme-linked immunosorbent assay (LAB-ELISA) for detecting antibody to infectious laryngotracheitis (ILT) virus in chicken sera was developed and compared with ordinary ELISA. Purified ILT virus, biotin-labeled anti-chicken IgG rabbit IgG conjugate, and horseradish-peroxidase-labeled avidin were used in the LAB-ELISA. When sera from farm chickens were tested by serum neutralization (SN) and two kinds of ELISA, the correlation rate between SN and LAB-ELISA was 50/50 (100%), and that between SN and ordinary ELISA was 39/50 (78%). In LAB-ELISA, all of the sera that were antibody-negative by SN had low absorbance (A) values (below 0.05), and the A values were closely correlated with the SN indexes. In ordinary ELISA, however, the sera antibody-negative by SN had various A values ranging from 0.06 to 0.32. LAB-ELISA had much lower nonspecific reactions than ordinary ELISA against sera from ILT-negative chickens, even when chickens were 30 weeks old. ILT antibody production after ILT vaccination could be detected by LAB-ELISA. A values peaked 5 weeks postinoculation and were maintained for 17 weeks.

Animals↗

PubMedDate not supplied

Changes of insulin and glucagon receptors following bile duct ligation and its release.

The specific bindings of insulin and glucagon to 4 x 10(4) g pellets containing hepatic plasma membrane were measured at 1 and 2 weeks after bile-duct ligation and 1 week after reduction of jaundice. At 1 week of jaundice, insulin binding was not decreased compared to control rats, however, glucagon binding 30(6)% was significantly lower than that 43(8)% in control rats (p < 0.01). At 2 weeks of jaundice, insulin binding 35(3)% was significantly lower than that 40(5)% in control rats (p < 0.05), and glucagon binding 26(4)% was also significantly lower compared to control rats 42(4)% (p < 0.01). The decreased insulin and glucagon receptors returned to nearly the levels of controls after 1 week's reduction of jaundice. These results suggested that the measurement of receptor binding may be useful as an indicator of the severity of hepatocyte injury.

Animals↗