Cell Disintegration

Necrosis is a dramatic and very rapid form of cell death in which essentially every compartment of the cell disintegrates 613... 

Necrosis is a dramatic and very rapid form of cell death in which essentially every compartment of the cell disintegrates. Necrosis is characterized by marked dysregulation of ion homeostasis resulting in cell swelling, dilation of mitochondria and the ER and the formation of vacuoles in the cytoplasm [33], Proteases play important roles in the degradation of cells during necrosis. In contrast to apoptosis, where caspases are the key death proteases, calpains and lysosomal proteases (cathepsins B and D, in particular) are major players in necrosis. Caspases may be activated in response to mitochondrial damage and... 

Many cells, especially bacteria, yeast, etc., require very drastic measures to disrupt them and various cell disintegrators are available for this purpose. Ultrasonic vibrations cause the formation of minute bubbles, a phenomenon known as cavitation, which is caused by the extreme variations in pressure generated by the sound waves, although the generation of heat may cause problems unless the samples are cooled frequently during the treatment. An additional... 

Fig. 15.1. Schematic representation of morphologic changes in a cell during apoptosis. On reception of an apoptotic signal, an adhesive cell (a) begins to become rounded (b) and the nuclear DNA condenses (c). The DNA is fragmented and the nucleus begins to break down into discrete chromatin bodies (d). Finally, the cell disintegrates into several vesicles (apoptotic bodies) (e), which are phagocytozed by neighboring cells (f).

When an ovum is formed three cells disintegrate and become polar bodies in sperm formation all four cells develop into spermatozoa... 

Qactivation 40 9 keal/mol (Refs 4 11) insol in w, dil acid or alk, neutral to litmus (Refs 1 2). This compd is a powerful poison, especially injurious to the liver and moderate red cell disintegration occurrs from azopropane intoxication (Ref 3)... 

Vanadate stimulates protein kinases in the cytosol, as demonstrated in adipose cells and extracts. The activation of a membrane and cytosolic protein tyrosine kinase have been demonstrated in adipocytes, and the membranous enzyme has been postulated to be a way to involve PI-3K actions without activation of insulin receptor substrate-1 (IRS-1) in the insulin signal transduction pathway [140], It is always difficult to determine if protein kinase activation is direct or the result of stimulation of a protein phosphatase. The fact that kinase stimulation was seen in isolated extracts after cell disintegration in this adipocyte cell system supports the idea that vanadium addition to cells could directly stimulate kinases via an as-yet-undetermined mechanism. In other experiments with 3T3-L1 adipocytes bis(acetylacetonato)oxovana-dium (IV) BMOV and bis(l-N-oxide-pyridine-2thiolato)oxovanadium (TV) caused increased tyrosine phosphorylation of both the insulin receptor and IRS-1 in a synergistic way with insulin, as measured by antibodies to phosphotyrosine residues [141]. 

The prognosis of HE with acute liver failure is generally very bad. Lethality is 80-85% this can diminish or increase, depending on the acuteness and severity of liver cell disintegration. (1, 2, 14, 20, 39, 113)... 

Depending on the time period involved in the course of the disease, acute liver failure without pre-existing liver disease can initially be differentiated by massive liver cell disintegration due to a variety of causes. In contrast, chronic liver insufficiency with pre-existing liver disease is mostly found in advanced liver cirrhosis with a progressive loss of function. A sudden necrotising episode is also able to precipitate the change from chronic and still compensated liver insufficiency into acute liver failure ( acute on chronic ) in the same way that acute liver failure which has been overcome can develop into chronic liver insufficiency. 

Very early swelling of organelles cells disintegrate and lyse, appear chaotic, form blebs early (organelles are not found in blebs)... 

The most frequently applied technique for cell disintegration of yeast is autolysis. The cell wall is digested by yeast-bome proteases. The process may be supported by externally added proteolytic enzymes from other sources and/or acid or alkali. Consecutively biomass is separated and the aqueous filtrate further processed. In many cases simple concentration by evaporation and drying is sufficient for the production of the yeast extracts or autolysates. 

Cumming, R.H. Iceton, G. Cell disintegration and extraction techniques. In Protein Purification Techniques, 2nd Ed. Roe, S., Ed. Oxford University Press Oxford, 2001 83-108. 

Cell disintegration In the case of intracellular products, cells need to be lysed by high-pressure homogenization, by wet milling, or by enzymes, detergents, and other chemicals that disintegrate the cell wall and membrane. 

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