monocyte Biol.
(ˈmɒnəsaɪt)
[ad. G. monozyt (Pappenheim & Ferrata 1910, in Folia Haematologica X. i. 81): see mono- and -cyte.]
A kind of large leucocyte which has a single oval or indented nucleus and no coarse granulation in the cytoplasm, constitutes 3–8 per cent of the total leucocytes in human blood, and is the circulating form of the macrophage.
| 1913 Stedman Med. Dict. (ed. 2) 556/1 Monocyte. 1927 A. Piney Rec. Adv. Hæmatol. ii. 16 The large hyaline leucocyte or monocyte is not easy to place with certainty into either the granular or the non-granular group. 1970 T. S. & C. R. Leeson Histology (ed. 2) viii. 140/1 Monocytes migrate readily through vessel walls and develop into phagocytic cells which cannot be distinguished from macrophages already present within the connective tissues. They are effective in combating tubercle bacilli. 1974 Passmore & Robson Compan. Med. Stud. III. xxi. 5/1 Absence of monocytes or basophils from the blood film or reduction in their number does not have clinical significance. |
Hence monoˈcytic a.; monocyˈtosis [-osis], an abnormal increase in the number of monocytes in the blood.
| 1914 Stedman Med. Dict. (ed. 3) 576/1 Monocytosis. 1934 Webster, Monocytic. 1935 Whitby & Britton Disorders Blood i. 18 The origin of the monocytic cells has been and still is, the subject of much controversy. 1938 H. Downey Handbk. Hematol. I. v. 389 Monocytes may appear in large numbers in the peripheral blood in the monocytic leucemias. Ibid. II. xv. 1067 In chronic malaria, the irritation of the reticulo-endothelium often leads to a monocytosis in the peripheral blood. 1972 Nature 4 Feb. 275/1 Cells of the monocytic series. 1974 Passmore & Robson Compan. Med. Stud. III. xxi. 5/1 Monocytosis is seen in the course of infectious mononucleosis and in some bacterial infections, notably tuberculosis. |