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I Kochan

Publications and source records attributed to I Kochan.

23 records · Page 2Linked to original sources
PubMed1969

Mechanism of tuberculostasis in mammalian serum. II. Induction of serum tuberculostasis in guinea pigs.

The growth of tubercle bacilli in serum samples of untreated animals depends upon the availability of ionic iron which serves as a growth factor in supporting bacillary multiplication. The amount of available iron in serum is determined by the ratio between iron-saturated and iron-free transferrin; a low value for the ratio is associated with tuberculostasis (e.g., human serum, 0.4), whereas a high value is associated with the growth-supporting quality (e.g., guinea pig serum, 5.6). The treatment of guinea pigs with lipopolysaccharide of Escherichia coli or tuberculous cell wall material consistently and significantly reduced serum iron levels; a similar but less striking effect was observed in BCG-vaccinated animals. Pronounced differences were observed in the time of appearance and duration of serum hypoferremia; in lipopolysaccharide-treated animals, it appeared in 1 day and lasted for several days, whereas in BCG-vaccinated animals it appeared in about 2 weeks and lasted for much longer time periods. The induced hypoferremia was always associated with the concomitant development of serum tuberculostasis which could be neutralized by the addition of iron. These results indicate, therefore, that the mechanism of induced serum tuberculostasis in lipopolysaccharide- or tuberculous cell wall-treated and BCG-vaccinated guinea pigs is the same as that present in tuberculostatic sera of untreated animals.

Animals↗
PubMed1969

Respiration-enhancing effect of tuberculin on splenic cells of hypersensitive guinea pigs.

Oxygen utilization in splenic cells of normal and BCG-sensitized guinea pigs was measured in a Warburg respirometer in the absence and in the presence of Old Tuberculin (OT). In the absence of OT, normal and sensitive cells respired at the same rate; in the presence of OT, normal cell respiration remained unchanged, whereas the respiration of sensitive cells increased significantly. This enhancement of oxygen utilization in sensitive cells was induced with OT but not with Purified Protein Derivative and it was most pronounced during the first hour of the interaction between the cells and the antigen. When normal splenic cells were treated with an extract of hypersensitive cells, their respiration was enhanced in the presence of OT. Oxygen utilization in cells of desensitized animals did not differ from that in cells of normal animals. The absence of reactivity to OT in splenic cells and in the skin of desensitized guinea pigs suggested that both phenomena are expressions of antigen-induced biological changes in cells of animals with delayed hypersensitivity.

Animals↗