[The effect of polysaccharide from typhoid bacteria on hemopoietic stem cells]

A study was made of dynamics of the content of colony-forming units (CFU) in the spleen and the bone marrow of the nonirradiated F1 (CBA times C57BL) mice to which polysaccharide (PS) from typhoid bacilli was administered. A method of exogenous colony formation was used in this work. A single PS administration increased the CFU count in the bone marrow (2-2 1/2 times) and in the spleen (3 times). Repeated (6- and 9- time) administration of PS was not more effective than a single one. Apparently PS acted as an inductor which caused proliferation of the stem hemopoietic cells and maintained this process for a definite period of time automatically.