1. Mammalian erythrocytes swell as the pH of the isotonic suspending medium is lowered, as a direct consequence of the specialized permeability properties of the erythrocyte membrane. Lymphocytes and granulocytes from a variety of sources did not exhibit this property. 2. The behaviour of mouse bone marrow erythroid cells at various stages of differentiation was studied by using a change in buo...

To gain insight into the clonal organization of lymphoid organs, we studied the distribution in situ of donor-derived cells in near-physiological chimeras. We introduced RT7b fetal liver cells into nonirradiated congenic RT7a neonatal rats. The chimerism 6-20 wk after injection ranged from 0.3 to 20%. The numbers of cell clones simultaneously contributing to cell generation in a particular hist...

Chronic wasting disease (CWD), a transmissible spongiform encephalopathy (TSE) of deer and elk, is one of a group of fatal, neurologic diseases that affect several mammalian species, including human beings. Infection by the causative agent induces accumulations of an abnormal form of prion protein (PrPres) in nervous and lymphoid tissues. This report documents the presence of PrPres within ecto...

This paper reviews scanning electron microscopic observations of cellular elements forming various lymphoid organs. The reticular cells in the secondary lymphoid organs are stellate, smooth-surfaced forms extending slender processes to comprise a three-dimensional network. The reticular fibers are usually covered by reticular cell processes, though they are naked in certain regions. Other types...

Lymphotoxin β-receptor (LTβR) and TNF receptor-1 (TNFR1) are important for the development of secondary lymphoid organs during embryonic life. The significance of LTβR and TNFR1 for the formation of lymphoid tissue during adult life is not well understood. Immunohistochemistry, morphometry, flow cytometry, and laser microdissection were used to compare wild-type, LTβR(-/-), TNFR1(-/-) spleens w...

By G. BRECHER, M.D., K. M. ENDICOTT, M.D., H. GUMP, A.B., AND H. P. BRAWNER H EINEKE,’ investigating effects of x-rays on internal organs, found the lymphoid tissues peculiarly susceptible to irradiation. This observation suggested the possibility of studying the function of the lymphoid apparatus by observing animals deprived of their lymphoid tissue by means of selective injury by x-ray.2 For...

Tissue-specific interactions with specialized high endothelial venules (HEV) direct the homing of lymphocytes from the blood into peripheral lymph nodes, mucosal lymphoid organs, and tissue sites of chronic inflammation. These interactions have been demonstrated in all mammalian species examined and thus appear highly conserved. To assess the degree of evolutionary divergence in lymphocyte-HEV ...

By G. BRECHER, M.D., K. M. ENDICOTT, M.D., H. GUMP, A.B., AND H. P. BRAWNER H EINEKE,’ investigating effects of x-rays on internal organs, found the lymphoid tissues peculiarly susceptible to irradiation. This observation suggested the possibility of studying the function of the lymphoid apparatus by observing animals deprived of their lymphoid tissue by means of selective injury by x-ray.2 For...

Previously (1) it was demonstrated that, in the strain combination of mice under study, acquired tolerance to skin homografts was lost with increasing age. The chronic rejection pattern suggested a host versus graft reaction which increased in severity with time, culminating in the elimination of donor lymphoid cells and skin grafts. Since the rejection of homologous tissues by normal animals i...