Interleukin-2 (IL-2) is a potent growth factor that mature T lymphocytes synthesize and use as a proliferation signal. Much controversy has arisen concerning whether it is used to drive the extensive proliferation of immature pre-T cells in the thymus. Immature thymocytes acquire the competence to express IL-2 at an early stage, but it has remained uncertain whether they are activated to exerci...

In vitro cultures of spleen cells (S) from normal 8-10-wk-old DBA/2J mice were shown to develop a small number of plaque-forming cells (PFC) that released antibodies lytic to syngenic and autologous thymus cells as well as to syngenic lymphoma L5178Y cells used as the target in the PFC assay. A marked increase in the number of PFC detectable on L5178Y target cells was demonstrated on day 4 in t...

Cancer cells, however, continue to grow and divide, and can spread to other parts of the body. These cells accumulate and form tumors (lumps) that may compress, invade, and destroy normal tissue. If cells break away from such a tumor, they can travel through the bloodstream, or the lymph system to other areas of the body. There, they may settle and form "colony" tumors. In their new location, t...

Part Three addresses communicable diseases in four color-coded sections based on mode of transmission (airborne; fecal-oral; direct and indirect contact; and blood and sexual contact) and contains a discussion of 26 common communicable diseases that consider the prevalence, transmission, diagnosis, treatment, and prevention of each disease. The discussion of each disease is four to six pages in...

A brief explanation of cellular and humoral immunity. Although immunity involves every orvm and system of the body, the typical conceptualization of the immune system consists of lymphocytes divided into two major divisions: the humoral mid cellular aspects. Humoral immunity includes primarily B lymphocytes and has to do with antigen/antibody reactions. These are the reactions involved in type ...

The effect of the thymus gland in producing tetany is due to a specific tetany toxin produced by and contained in the thymus, and the thymus gland must be added to the group of glands for which the function of internal secretion has been demonstrated.

When CY-treated mice were given sheep red blood cells the serum hemagglutinin titers produced were significantly lower than those found when mice received SRBC but not CY. Titers could be raised to the levels found in the latter group if, in addition to SRBC, the CY-treated mice received 2 x 10(7) normal syngeneic spleen cells or a mixture containing 1.2 x 10(8) normal thymus and 1.2 x 10(8) no...