The influence of beryllium on cell survival rates in theIn-vitro culture system, on intracellular DNA synthesis and on SRBC-IgM antibody production responses

Immunocytotoxicity of beryllium (Be) was evaluated by studying cell viability, intracellular DNA synthesis and SRBC-IgM response in an in-vitro culture system using non-sensitized spleen cells of a C57BL mouse. Be addition showed a suppressive effect on cell viability, an enhancing effect on DNA synthesis and on IgM antibody production. The suppressive effect on cell viability manifested itself markedly as the concentration of Be was increased or the culture time was prolonged. The DNA synthesis-enhancing effect was noted at a relatively low concentration of Be (not more than 10μM). The enhancing effect on the IgM response was related to Be concentration at not more than 20μM. The experimental results mentioned above speculate that the cytotoxicity of Be shows a conflicting pattern of enhancement or suppression according to the concentration used and that immunologically it has a modulating effect or an activating effect on the immunocompetent cells

Cytometric and electron microscopic studies of the direct interaction of divalent nickel with intact and chemically modified HuT-78 lymphoblasts

Cytometric and ultrastructural studies on 24 hr cultures of intact, 1.0 mM H5IO6, and 0.1 mM SeO2-oxidized HuT-78 lymphoblasts were performed after their direct, 30 min interaction with 1.0 mM NiCl2. Except for moderately depressed cell viability, divalent nickel did not alter the progression of intact and oxidized target cells through the phases of the cell cycle. Although the plasma membrane remained structurally intact, marked distortion of mitochondria structure and increased osmiophilia were an invariable attribute of all nickel-pulsed cells. Moreover, numerous electron-opaque, intracellular depositions were detected in SeO2-oxidized, nickel-pulsed cells. It is concluded that the initial state of plasma membrane, and the interaction of nickel with other trace elements, have jointly determined the response of HuT-78 cells to brief and direct, divalent nickel pulses