south-to-north gradient in distribution of the r determinant of hepatitis b surface antigen in japan.a total of 2.305 sera positive for hepatitis b surface antigen were obtained from asymptomatic carriers throughout japan and subtyped for the d, y, w, and r specificities by the hemagglutination inhibition method. determinant d prevailed in japan (d, 99.1%; y, 0.9%), and there was no regional variation in its occurrence. in sharp contrast, there was a marked variation in the distribution of the w and r determinants, forming an apparent south-to-north gradient of r. the percentage of r determinan ...197547883
Displaying items 1 - 1 of 1