Normal and Pathological Fragmentation of Red Blood Cells; The Phagocytosis of These Fragments by Desquamated Endothelial Cells of the Blood Stream; The Correlation of the Peroxidase Reaction With Phagocytosis in Mononuclear Cells

Abstract

In 1917, Rous and Robertson (1, 2) demonstrated that there is a constant fragmentation of red cells in the circulating blood of the normal animal. They drew blood directly from the hearts of mammals into gelatin-Locke-citrate and obtained microcytes and poikilocytes by differential centrifugation. They observed that fragmentation was increased in anemia and also by such mechanical factors as pressure and heat. The process had been seen by many observers; for example, by Ehrlich (3), Arnold (4), Schwalbe (3, 6), Max]mow (7), Weidenreich (8), and others, with varying interpretations, but it was Rous and Robertson who determined that it is a constant and, in their judgment, the major factor in the destruction of red cells.We have been able to confirm the concept that there is a constant fragmentation of red ceils in the circulation of the normal rabbit by the study of films of fresh blood, and have found that the fate of these fragments is to be taken up by the so called clasmatoeytes or wandering endothelial phagocytes. We shall use the three terms: clasmatocyte, wandering endothelial phagocyte, and macrophage as synonymous and distinct from monocyte. Clasmatocytes with fragments of red cells are to be found in the circulating blood, in the spleen, and in the connective tissues, and we think that they can be discriminated, when studied with the supravital technique, from eosinophilic leucocytes, with which they have been confused in the literature. Thus,

The Relation of Monocytes and Clasmatocytes to Early Infection in Rabbits With Bovine Tubercle Bacilli

“…The latter is entirely comparable with the usual monocyte of rabbit blood, the basic muddy blue cytoplasm typical of all cells Of this type being independent of species and granulation. With reference to this strain of cells in the two species, the peroxidase reaction has been found (14) to parallel the azurophilic granulation qualitatively and quantitatively, the majority of human monocytes giving a positive oxidase reaction, the opposite being true of the rabbit monocyte.…”

“…The color and nature of the vacuoles reacting to neutral red are identical in all species, their relative number on]y influencing the sharpness of definition of the clearly maintained centrosphere. In the specific reaction to tubercular infection, the epithelioid and giant cells of rabbit and human tissues are indistinguishable in their characteristic reaction to vital dyes, while obeying the species response to the peroxidase reaction (14); rabbit epithelioid, oxidase-negative, human epithelioid, oxidasepositive. The cells in locomotion are stretched out often in triangular shape; there is a slow progression with less active streaming of particles than with the granulocytes; in the supravital technic, the surface films do not have as free play, due to the narrowness of the space between slide and cover-sliD, as in the tissue culture preparations.…”

Non-Myeloid Cell Phagocytosis

“…Significant cross talk occurs between endothelial cells and professional phagocytes as the endothelium allows leukocytes to cross through the barrier into tissues during times of infection and stress [129]. The concept of endothelial cells acting as phagocytes is not new, with some reports dating back as early as the 1920s [130]. Such a process is important for the endothelium to maintain circulatory homeostasis with effective phagocytic clearance mechanisms [129].…”

Mudanças em subgrupos de monócitos durante infecção aguda pelo vírus da imunodeficiência símia (SIV); expansão de uma população inédita de células CD14+CD16- com um fenótipo atípico CCR2-

“…Até por volta de 1920, fagócitos mononucleares do sangue eram independentemente chamados de leucócitos endoteliais de Mallory, histiócitos sanguíneos de Aschoff, e grandes leucócitos mononucleares de Ehrlich, e ainda hoje não está evidente quando a palavra monócito apareceu na literatura pela primeira vez (Doan, 1926;Doan and Sabin, 1926 (Sabin, 1921). Sabin também confirma as observações feitas por outros investigadores de que dois tipos celulares distintos pertencentes à linhagem monocítica povoam o sangue: os "leucócitos mononucleares grandes", geralmente arredondados com um núcleo levemente acêntrico com chanfraduras, e uma "célula de transição", geralmente irregular com "partículas um tanto ativas no citoplasma" (Sabin, 1923 Subpopulações com funções similares foram encontradas em camundongos e ratos, embora outros marcadores de superfície (Ly6C, 7/4) sejam usados para tal classificação Kim et al, no prelo;Sunderkotter et al, 2004).…”