Antigen-binding cells in central and peripheral lymphoid tissues of the rabbit

Appendectomy and subsequent cancer risk

Although earlier epidemiologic studies reported a positive association between appendectomy and certain cancers, interest was limited due to lack of confidence in the study findings. However, recent morphologic studies on the immune structure of the vermiform appendix in the rabbit and man argue for a reevaluation of the appendectomy--cancer association. This paper reviews briefly the morphologic and epidemiologic literature on the subject to date. The validity of the earlier epidemiologic findings is discussed and avenues for further research assessing the relationship of appendectomy to subsequent cancer risk are proposed.

Germinal centres and the B cell system. IV. Functional characteristics of rabbit appendix germinal centre (-derived) cells

Functional capacities of rabbit appendix germinal centre cells were tested in appendectomized, 450 rads X-irradiated rabbits, reconstituted with autologous appendix germinal centre cells, which are obtained by mechanical separation--"stripping"--of the appendix. For comparison, functional capacities of appendix germinal centre derived cells were tested in rabbits, 450 rads X-irradiated with the appendix shielded. In both types of experimental systems, slow restoration of primary IgM responsiveness to Salmonella Java paratyphi-B (PAR) was observed; in contrast, the capacity for memory cell production (of both mu and gamma-type) to PAR was restored very early in both systems. These results suggest germinal centres to be antigen dependent microenvironments for selective as well as non-selective amplification of immature B cells, which after subsequent maturation become part of the pool of either memory or virgin mature B cells respectively.