Changes concerning the external structure of peritoneal macrophages, due to the DQ-12 standard dust.

The cytotoxic activity of the DQ-12 standard dust on the external structure of peritoneal macrophages, after intraperitoneal introduction, was investigated, vs nontreated macrophages, and kept in in vitro cultures for 3, 6, and 24 hr. The alterations related to the external structure were investigated by scanning electron microscopy (SEM), clearly showing that cell damage can take place when the dust contacts the external surface of the cell, as already shown by the work of Johnson and Davies (paper presented at the International Workshop on the in Vitro Effects of Mineral Dusts, South Wales, U.K., 1979) and Miller (Environ. Res. 20, 162-182, 1979).

[Isolation of a Pasteurella multocida bacteriophage]. / Isolierung eines Pasteurella-multocida-Bakteriophagen.

Lysogenesis testing of 84 Pasteurella multocida strains resulted in detection of one lysogenic strain from which phage B225 was isolated. B225 lysed only one Pasteurella multocida strain isolated from cattle. The Pasteurella phage, when examined by electron microscopy, showed a hexagonal head and a non-contractile, Flexible tail, It could be attached, consequently, to Group B according to Bradley (1967).

Examination of human and animal leukemic cells by high contrast scanning electron microscopy.

Investigation of human or animal (sheep and ox) leukemic cells by scanning electron microscopy enabled the identification and study of some ultrastructural details of the cell surface. A more detailed visualization by the high contrast technique of the same cell surface was obtained, in this work, for the first time in the biological field. This technique allows a better interpretation of any zone of the preparation examined, irrespective of the species from which the cells are collected.