The entire surface protein of hepatitis B virus serotype ayw containing the preS (preS1+preS2) and S domains has been expressed in the yeast Saccharomyces cerevisiae. Yeast containing a recombinant plasmid utilizing a constitutive promoter did not express this gene successfully due to the toxicity of the protein. A plasmid using a regulatable promoter directed expression which initiated late in the exponential phase of growth and resulted in the accumulation of high intracellular levels of the complete surface protein. The purified polypeptide aggregates into a form which, although not comprised of typical 20 nm particles, displays antigenic determinants encoded by the preS1, preS2 and S domains. Immunization of rabbits elicited the formation of antibodies directed against all three domains. This candidate vaccine will be useful for studying the contributions to viral immunity of the host response to the preS1 and preS2 domains.

Animals↗

PubMedDate not supplied

Surgery for small liver cancers.

During the last 16 years, we have resected small hepatocellular carcinomas (HCCs) measuring 5 cm or less from 362 patients, 266 of whom also had liver cirrhosis. The operative and hospital mortality rate were 1.7% and 1.9%, respectively. These showed a gradual decrease year by year in parallel with reduction of intraoperative blood loss achieved by the selective vascular occlusion technique and Pringle method. In 1989, 87% of hepatectomy patients were discharged without the need for whole blood transfusion, and 5-year survival was 43.7%. Tumor size, number of tumors, intrahepatic metastasis, vascular invasion, and capsular invasion were significant prognostic factors. Edmondson grade and the operative procedure employed were significantly related to outcome. Our standard policy for selection of operative procedures and perioperative care is described, and the selection of treatment modalities is discussed.

Adult↗

PubMedDate not supplied

Central bisegmentectomy of the liver: experience in 16 patients.

Fourteen patients with hepatocellular carcinoma and mild to moderate liver dysfunction and 2 with metachronous liver metastases from rectal cancers underwent central bisegmentectomy of the liver, i.e., en bloc removal of the left medial and right anterior segments. One patient who had undergone preoperative liver artery embolization died in the hospital. Four patients survived without relapse 60-135 months postoperatively. Eleven patients had recurrent tumors, all in the liver remnant, and 2 also had recurrent tumors in the lungs. Six patients who relapsed died 28-93 months postoperatively. Four were alive with disease at 7-89 months, 1 after a second liver resection 54 months after central bisegmentectomy. Six of the 16 patients survived for 5 years or more. The results are favorable for these advanced tumors, often in the presence of liver dysfunction. The indications, technique, and results are discussed.

Aged↗