Hepatitis B virus (HBV) DNA was studied in liver DNA of 23 patients with primary hepatocellular carcinoma and in white blood cell DNA of 11 of these patients by Southern blot hybridization analysis probed with 32P-labeled HBV DNA cloned in plasmid pBR325. Of the 23 hepatoma DNA samples, 16 were positive for HBV DNA, and 15 of these showed integration of HBV DNA into the host liver DNA. In 5 patients, free HBV DNA was found in addition to integrated HBV DNA and in only one was free HBV found alone. All patients serologically positive for HBV surface antigen (HBsAg) were positive for HBV DNA in tumor samples. The pattern and the degree of hybridization differed considerably among different cases. HBV DNA was found in tumor and in adjacent nontumor tissue in two patients. Of 11 white blood cell DNA samples, two were positive for HBV DNA. The HBV DNA in the white blood cells was not integrated into the host DNA. In the undigested white blood cell DNA, the free HBV DNA gave a positive signal at 5.5 kb and often also at 9.5 kb. After Eco RI digestion, these 5.5-kb and 9.5-kb positive fragments disappeared, while a strong positive band at 3.2-kb appeared. Hind III digestion produced the same positive fragments as in the undigested white blood cell DNA and failed to produce the 3.2-kb fragment. Sometimes, especially after Hind III digestion, a positive fragment at a position corresponding to about 16.2 kb was also demonstrable in addition to the 5.5-kb and 9.5-kb positive fragments.(ABSTRACT TRUNCATED AT 250 WORDS)

This study revealed that, in terms of CYP2D6 polymorphism, Malaysian Chinese were a heterogeneous group of people. Although sharing some similarities with other Orientals, they also seemed to have some notable differences. The alleles CYP2D6*4, *5, *9, *10 and *17 were all detected. CYP2D6*3 was however absent.

A starch-gel electrophoretic study of Hb Bart’s in newborns of different racial groups in West Malaysia showed its presence in 7% of 568 Chinese, 4.9% of 205 Malay, and 1.8% of 226 Indian newborn babies. Quantitation of Hb Bart’s by cellulose acetate electro phoresis revealed the existence of two groups, one with levels of 1.6–3.2%, the other with 5.1–12.3%. Levels of Hb Bart’s in 26 of the Chinese, 5 of the Malay, and none of the Indian infants exceeded 5%; in 13 of the Chinese, 5 of the Malay, and 4 of the Indian newborns they were less than 3.2%.

An abnormal, fast-moving 5'-nucleotide phosphodiesterase isozyme was found in 90.0% of 20 Malaysian patients with primary hepatoma and in 23.5% of 391 Malaysian patients with various malignant diseases; it was also discovered in 42.9% of 14 Malaysian and American patients with clinically active hepatitis B infection; in 16.7% of 18 healthy American blood bank donors who were positive for hepatitis B surface antigen (HBsAg); in 13.9% of 287 healthy Malaysian blood bank donors, some positive for HBsAg; and in none of 160 healthy American donors who were negative for HBsAg. A correlation of this abnormal isozyme with hepatoma and with infectious hepatitis B is clearly evident.