The signs of necrosis are the same as those of irreversible cell injury —that is, cell membrane rupture and nuclear changes, such as pyknosis, karyolysis, and karyorrhexis. What does the term mean in medical terms? [term] 1. a definite period, especially the period of gestation, or pregnancy. 2.
What is karyorrhexis?
The irreversible condensation of chromatin in the nucleus of a cell undergoing necrosis or apoptosis. What is Karyorrhexis? The destructive fragmentation of the nucleus of a dying cell whereby its chromatin is distributed irregularly throughout the cytoplasm.
What is pyknosis and karyolysis?
Karyolysis. Disintegration of the cytoplasm, pyknosis of the nuclei, and karyolysis of the nuclei of scattered transitional cells may be seen in urine from healthy individuals as well as in urine containing malignant cells. Cells with an attached tag of partially preserved cytoplasm were initially described by Papanicolaou...
What are the morphological characteristics of karyolysis?
Morphological characteristics of karyolysis and other forms of nuclear destruction. Karyolysis (from Greek κάρυον karyon— kernel, seed, or nucleus), and λύσις lysis from λύειν lyein, "to separate") is the complete dissolution of the chromatin of a dying cell due to the enzymatic degradation by endonucleases.
What happens during karyorrhexis?
Karyorrhexis is the rupture of the nuclear membrane, division of chromatin into small basophilic granules and spreading into the cytoplasm.
Is nuclear pyknosis irreversible?
Pyknosis has been considered as an irreversible condensation of chromatin and the nucleus. It commonly occurs in both apoptotic and necrotic cell death.
What causes karyorrhexis?
MPT is caused by many mechanisms, including oxidative stress, and some xenobiotics, such as salicylic acid, increase PT pore opening by a calcium-dependent mechanism. The multiple programs of cell death are evolutionarily conserved.
Is karyorrhexis seen in apoptosis?
Neutrophils that undergo programmed cell death (apoptosis) exhibit pyknosis and karyorrhexis.
What is reversible and irreversible cell injury?
Cell injury is classified as reversible if the injured cell can regain homeostasis and return to a morphologically (and functionally) normal state. Acute cell swelling is the classic morphologic change in reversible injury; however, it is also the typical early change of irreversible cell injury.
What cell injury is irreversible?
Irreversible responses of cell injury refer to changes that lead to a new equilibrium with the environment. Types of irreversible responses include: interruption of membrane integrity; hydrolysis of phospholipids, proteins and nucleic acids; and necrosis, where organelles undergo a sequence of changes.
Is swelling of endoplasmic reticulum reversible?
Intracellular polycationic molecules cause reversible swelling of the rough endoplasmic reticulum.
Is rupture of cell membrane reversible?
Cell injury can be reversible or irreversible. Hypoxia is the most important cause of cell injury. Irreversible cell injury can be recognized by changes in the appearance of the nucleus and rupture of the cell membrane.
What are karyorrhexis cells?
Definition: Karyorrhexis is the destructive fragmentation of the nucleus of a dying cell whereby its chromatin is distributed irregularly throughout the cytoplasm. It is usually preceded by pyknosis and can occur as a result of either programmed cell death (apoptosis ), senescence, or necrosis .
Does karyolysis happen in apoptosis?
It is usually associated with karyorrhexis and occurs mainly as a result of necrosis, while in apoptosis after karyorrhexis the nucleus usually dissolves into apoptotic bodies.
Does karyolysis occur in necrosis?
As mentioned before, karyolysis is a general morphological change in necrotic cells. However, the generation mechanism has not been clarified.
Is karyolysis seen in apoptosis?
Oncosis is therefore used to describe a process that leads to necrosis with karyolysis and cell swelling whereas apoptosis leads to cell death with cell shrinkage, pyknosis, and karyorrhexis.
What is nuclear pyknosis?
Pyknosis involves the shrinkage or condensation of a cell with increased nuclear compactness or density; karyorrhexis refers to subsequent nuclear fragmentation (Fig. 5-29, F). Pyknosis and karyorrhexis are degenerative changes that are often observed in nonseptic exudates.
Is swelling of endoplasmic reticulum reversible?
Intracellular polycationic molecules cause reversible swelling of the rough endoplasmic reticulum.
What are the 4 types of necrosis?
These are coagulative, liquefactive, caseous, gangrenous which can be dry or wet, fat and fibrinoid. Necrosis can start from a process called “oncosis”.
What is pyknosis in medical term?
Medical Definition of pyknosis : a degenerative condition of a cell nucleus marked by clumping of the chromosomes, hyperchromatism, and shrinking of the nucleus.
What are the morphological characteristics of karyolysis?
Morphological characteristics of karyolysis and other forms of nuclear destruction. Karyolysis (from Greek κάρυον karyon— kernel, seed, or nucleus), and λύσις lysis from λύειν lyein, "to separate") is the complete dissolution of the chromatin of a dying cell due to the enzymatic degradation by endonucleases. The whole cell will eventually stain ...
What happens to the whole cell after karyolysis?
The whole cell will eventually stain uniformly with eosin after karyolysis. It is usually associated with karyorrhexis and occurs mainly as a result of necrosis, while in apoptosis after karyorrhexis the nucleus usually dissolves into apoptotic bodies.
Is the dermis a suppurative inflammatory response?
The dermis and subcutis exhibit mainly a suppurative inflammatory response with focal necrosis and marked karyorrhexis. Pseudocyst formation has also been noted with numerous organisms within these cystic spaces that are lined by neutrophils. There is usually little, if any, granulomatous formation. The lesions can be mistaken for a Sweet-like reaction pattern. Organisms are easily visible after staining with acid-fast stains. The Fite stain is sometimes more consistently positive. Reportedly, the organisms are characteristically focally gram positive. Culture must be performed to rule out other causes of the infection.1,161
Can corticosteroid therapy cause eosinophil degeneration?
Corticosteroid therapy may interfere with a diagnosis of CEP because it will produce a reduction in intact eosinophils and can cause significant eos inophil degeneration with karyorrhexis. The degenerated, fragmented cells can be misinterpreted as neutrophils, yielding a diagnosis of abscess with an implication of bacterial infection, which prompts a different therapeutic response than CEP. AEP has a more abbreviated clinical course and does not show the subacute and chronic histologic changes of CEP. Desquamative interstitial pneumonia (DIP) is another important differential diagnostic consideration, particularly in macrophage-rich cases or corticosteroid-treated eosinophil-depleted cases, but the chest radiographic findings differ from CEP, and DIP will not be associated with peripheral blood eosinophilia, unlike CEP. Churg-Strauss syndrome often includes a component of eosinophilic pneumonia as one of its manifestations. The finding of necrotizing vasculitis in the context of an eosinophilic pneumonia should prompt consideration of this syndrome and stimulate evaluation for the other clinical and laboratory findings associated with this disorder. Langerhans cell histiocytosis may also be considered in the differential diagnosis, but demonstration of clusters of S100- and CD1a-positive Langerhans cells can separate the two disorders. Also, significant degrees of peripheral blood and BAL fluid eosinophilia are not found in association with Langerhans cell histiocytosis. Finally, pneumothorax causes eosinophilic pleuritis, and the eosinophils may extend into the subpleural lung parenchyma. In these cases, knowledge of the clinical picture and lack of peripheral blood eosinophilia will be helpful for determining the nature of the process.
