Toxicity of mercury to hybridoma TA7 cells

Environmental mercury and mercury compound contamination has increased dramatically since the industrial revolution. This paper describes the toxic effects of mercury on a culture of hybridoma TA7 cells, which produce antibodies against the A-subunit of viskumin. Cells were cultivated on 96- well flat-bottomed plates with RPMI-1640 medium supplemented with 10% fetal calf serum at 37°C in 5% CO2/95% air. The cells were exposed to 0.1nM/l- 10μM/l Hg2(NO3)2·2H2O (mercury nitrate) during the exponential growth phase. Toxicity was assessed by using the colorimetric MTT (tetrazolium) assay after exposure for 48 hours. Cell growth and cell survival were evaluated by using percentage indices of cellular content in exposed cells when compared to non-exposed control cells. The concentrations of the no- effect level, the lowest observed effect level and the the highest toxic effect level were registered. The toxic effects of the mercury compound on the hybridoma cells occurred between 0.1μM/l and 10μM/l.Peer reviewe

Composition of human islet cell preparations for transplantation

To study the cellular composition of human islet cell isolates for transplantation, formalin-fixed and paraffin-embedded cell pellets were stained by the immunoperoxidase method with a panel of antibodies characterising endocrine, epithelial, soft tissue and haematolymphoid components. Immediately after separation, the isolates contained 30-80% islet cells, differing mainly in the content of islet and acinar cells, whereas the soft tissue, ductal/ductular and haematolymphoid elements comprised a relatively constant 10-20%. After 1 week in culture the islet cell content of less highly purified isolates (30-40% islets) dropped dramatically to 5%. The highly purified isolates (70-80% islets) showed only a minimal change in cellular composition; however, approximately two-thirds of islet cells were degranulated and did not stain for insulin. Haematolymphoid components were still present in all cultured isolates. We conclude that primarily mechanical purification methods and short-term culture are not sufficient to eliminate highly immunogenic cells. In addition, short-term culture is deleterious to the isolate if a significant number of acinar cells is still present after enrichment. © 1992 Springer-Verlag