Methods:Serum vitamin A levels and IgA, IgG, IgM, C3, C4 and lysozyme concentrations were measured by microfluorimetric method, color simple agar diffusion and agar-plate methods respectively.

• 方法:分别采用微量荧光法、彩色单向免疫扩散法和平板法测定脐血血清VitA及血清IgG、IgA、IgM、补体C3、C4和溶菌酶的含量。