Hepatitis B e antigen and antibody in asymptomatic Chinese with hepatitis B surface antigenemia in Taiwan

Two hundred and twenty two asymptomatic carriers of hepatis B surface antigen (HBsAg) with age between 4 months and 68 years, 172 healthy persons with antibody to HBsAg (anti-HBs) and 85 healthy persons seronegative for both HBsAg and anti-HBs were studied by double immunodiffusion for the evaluation of the meaning of hepatitis B e antigen (HBeAg) and its antibody (anti-HBe). In 222 asymptomatic carriers, HBeAg was detected in 32.4% and anti-HBe in 31.5%. The geometric titer of HBsAg was 1:2159 in the HBeAg positive and 1:149 in the anti-HBe positive persons. Frequencies of HBeAg and anti-HBe in asymptomatic carriers of HBsAg correlated closely with age. The highest frequency of HBeAg was found in the first decade in 64% decreasing steadily to 20.8% in the fourth and then suddenly down to 4.1% in the fifth decade. A reverse trend was observed in anti-HBe frequency. From our analysis, it is likely that the high frequency of HBeAg in serum of Chinese, especially in females of fertile age, might be an important contributing factor for the high rates of hepatitis B virus (HBV) infection and HBsAg carrier in Taiwan. The presence of HBeAg/anti-HBe system is not only a market of infectivity and prognosis but also a chronologic marker of HBV infection.

Hepatitis A virus infection in Taiwan. A hospital-based study

One hundred and thirty-four healthy subjects and 220 patients with liver diseases were studied for antibody to hepatitis A virus (anti-HAV) with radio-immunoassay. The frequency of anti-HAV related closely to the age of healthy subjects; the rate of positivity increased with age, being 5.9% in those under four years, 13.3% in the late first decade and over 90% after the third decade. Taking meals at stalls with poor sanitary standards is suspected to cause the prevailing infection in teenagers, although a cohort effect due to environmental and socio-economic improvement can not be excluded. Anti-HAV was present in most patients with frequencies comparable to healthy subjects of the same age. It is concluded that in Taiwan the prevalent chronic liver diseases and hepatocarcinoma are unrelated to HAV infection and the patients are infected to an extent similar to healthy people of the same age.

Purification and properties of bovine brain calmodulin-dependent cyclic nucleotide phosphodiesterase

Calmodulin-dependent cyclic nucleotide phosphodiesterase was purified from bovine brain to apparent homogeneity by a new procedure involving DEAE-cellulose, Affi-Gel blue, calmodulin-Sepharose 4B, and Sephadex G-200 column chromatographies. The enzyme was purified more than 3,000-fold from the brain extracts with greater than 12% yield. The purified phosphodiesterase could be activated 10- to 15-fold by calmodulin and Ca2+ to a specific enzyme activity of more than 300 mumol of cAMP hydrolyzed/min/mg of protein. Molecular weight of the enzyme was determined to be 115,800 by the sedimentation equilibirum method or 124,000 from the sedimentation constant and Stokes radius of the protein. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the enzyme showed a single protein band with an apparent molecular weight of 58,000. These results suggested that the calmodulin-dependent phosphodiesterase from bovine brain has a subunit structure of alpha2. Molecular weight of the complex of calmodulin and phosphodiesterase was the complex of calmodulin and phosphodiesterase was also calculated from the sedimentation constant and Stokes radius to be 159,000. Since calmodulin has a molecular weight of about 17,000, the result indicated that the stoichiometry of the complex is calmodulin2 alpha2. The catalytic subunit of cylic AMP-dependent protein kinase was found to catalyze the phosphorylation of the purified phosphodiesterase with the incorporation of 2 mol of phosphate/mol of the enzyme.