pyknosis Cytology.
(pɪkˈnəʊsɪs)
Also pycnosis.
[f. Gr. πυκν-ός close, compact + -osis.]
The contraction of a dying cell, or of its nuclear material, into a densely staining mass or masses.
| 1900 Dorland Med. Dict. 552/1 Pyknosis, a thickening; especially degeneration of a cell in which the proto⁓plasmic substance becomes more dense and the size of the cell smaller. 1926 Arch. Neurol. & Psychiatry XVI. 135 In general there is a progressive shrinking and pyknosis of the nucleus. 1946 [see hyperchromatosis 2]. 1950 A. W. Ham Histol. v. 60 The changes that occur in nuclei as, or after, individual cells die in the living body are of three sorts. The commonest one is called pycnosis; this consists of a shrinkage of the nuclear material into a homogeneous hyperchromatic mass. 1972 Physics Bull. Mar. 147/1 The biological end points that will be studied include glycogen accumulation, nerve cell pyknosis, nerve cell injury or loss and glial reaction. 1978 Nature 25 May 306/2 In minced muscle grafts sarcoplasmic structure was rapidly lost, and most muscle nuclei seemed to undergo pyknosis, fragmentation and lysis. |