A human hepatoma cell line (PCL/PRF/5) produces lung metastases and secretes HBsAg in nude mice

PLC/PRF/5 is a human liver cancer cell line which synthesizes hepatitis B virus surface antigen (HgsAB). These cells produced tumor in 6 of 8 (75%) congenitally athymic nude mice at 13 of 28 subcutaneous injection sites and in 13 of 14 (93%) mice inoculated intraperitoneally. Tumors were successfully transplanted to 4 of 6 additional nude mice. Tumor growth was rapid. Growth of cephalad tumors was significantly greater than for caudal tumors (0.39 mm/day versus 0.28 mm/day). Microscopic examination of tumors showed moderately well-differentiated hepatocellular carcinoma. Foci of identical cells were present in pulmonary veins in 7 of 14 tumor-bearing animals. Tumor cell karyotype was identical with that of PLC/PRF/5 cells. In addition, HBsAg was detectable in high titer in animals with extensive tumor. Biological features of PLC/PRF/5-induced tumors in nude mice appeared to closely resemble human hepatocellular carcinoma. Moreover, HBsAg may provide a marker of tumor growth.

Circulating platelet aggregates: a chronic platelet activation in patients with transient ischaemic attacks

Platelet hyperaggregability was tested in 62 TIA patients by means of the formalin fixing principle of Wu and Hoak. Compared to age-matched controls, the platelet aggregates ratio (PAR) was reduced from 0.99 +/- 0.04 SD to 0.807 +/- 0.14 SD. This means a highly significant increase of circulating platelet aggregates (CPA) in untreated TIA patients, regardless of the interval sinche the last attack (from 2 days to 1 year). PAR was especially reduced in patients with abnormal angiography (expressing pronounced cerebral or diffuse ATS) and it was possibly affected by previous antiplatelet treatment with ASA.