The rat testis and liver or human liver microsomes were used for 11β-HSD1 assay. 11β-HSD1 activity was performed in the microsome according to a previously described method  . In brief, the assay tubes contained 25 nM substrate 11DHC (for rat) or cortisone (for human), spiked with 30,000 cpm their respective 3 H-11keto-steroid, mM NADPH and 5 mM glucose-6-phosphaare in the PBS buffer. 2 µg microsomes were added to each tube to initiate the reaction and the reaction mixture was incubated for up to 2 hrs, during which the reaction is within the linear range. The rest procedure was similar to 11β-HSD1 assay in intact cells.
Jackson et al. (2001) reported a significantly reduced frequency of HLA class II type DQ7 allele in patients with variant CJD (vCJD; see 123400 ), but not in those with classical CJD. In a sample of 50 British Caucasians with variant CJD compared with 26 patients with sporadic CJD and 197 cadaveric controls, the frequency of the DQ7 allele was far reduced, being present in 12% of variant CJD patients versus 46% of sporadic CJD patients and % of the cadaveric controls (P = ). Individuals not carrying the DQ7 allele have a -fold relative risk of contracting variant CJD versus others who do carry the DQ7 allele. The DQ7 allele is also known as DQB1*0301/4/9.