pyknosis

Pyknosis and loss of neurons, especially of pyramidal cells may be related, apparently, with the action of ethanol and drugs.

Pyknosis, or shrunken nuclei, are characterized by a small shrunken nucleus, with a high density of nuclear material that is uniformly but intensely stained.

Farley (1969) mentioned "increased sarcomatoid cell pyknosis" in disseminated neoplasia of mussels that possibly referred to apoptotic chromatin condensation.

At the cellular level, the tubular cells showed pyknosis and cytoplasmic lysis (Fig.

Apoptotic cell nuclei presented in dark brown, the cytoplasm showed no color and the cell nuclei showed pyknosis. TUNEL-positive cells in the slices of each group could be seen in the light microscope.

On H&E-stained sections, neuronal pyknosis, swelling, torsion, and cell body deformation were present in rat cortex of DAI 3 d group while, in the control group, no similar abnormal histopathological changes were observed (Figure 1).

Later changes include necrotic changes (pyknosis and karyorrhexis of trophoblast), loss of trophoblast nuclear staining, and eventually ghost villi.

However, the hippocampal neurons in the model group exhibited clear pyknosis, nuclear invagination, karyorrhexis and increased numbers of lysosomes.

Our findings are also in accordance with Abdel-Gawad S K & Mohamed A K G (9) who observed that PCT was most severely affected followed by DCT in the form of vacuolated cytoplasm and necrotic changes in the form of nuclear pyknosis along with intratubular casts with desquamated renal tubular cells.