Cell lysis characteristics

Hemoglobinuria and hematin casts in the distal convoluted tubules and tubular lumens located in the medulla and papilla were reported in rats after a single dermal exposure to 107.1 mg/kg liquid phenol (Conning and Hayes 1970). These phenomena are probably related to red blood cell lysis and increased glomerular filtration of hemoglobin. Hemoglobinuria is characteristic of lethal or near-lethal exposures by the dermal route. 

In the case of plankton, cell lysis that occurs shortly after death causes ATP to be released into seawater. Like most biomolecules, ATP is rapidly degraded in seawater by microbes. Thus, high surfece concentrations in Figure 22.5 reflect a rapid supply supported by the high rates of plankton production characteristic of the photic zone. Below the surface, concentrations decrease with increasing depth beneath the photic zone and, hence, distance from the biosynthetic source of the ATP... 

For over 300 years, the quinoline family of drugs, and chloroquine in particular, has been used as the primary treatment for malaria. Recent studies have demonstrated that this drug inhibits the aggregation of free heme into hemozoin, allowing levels of monomeric heme to rise until cell lysis occurs. Although the determined structure of hemozoin makes the polymer termination scheme proposed by Sullivan et al. unlikely, hemozoin drug heme interactions appear critical in the inhibition mechanism. Thus, researchers have identified the characteristics of... 

There are several methods of cell lysis (Table 8.2) [1,2], but there is none that works with cells of all biological origins. Each technique has its advantages and disadvantages, and the specific method of choice depends on the cell characteristics, the cell type, and the final application. A combination of more than one method may also be used. For example, enzymatic lysis uses specific enzymes to target the cell wall. However, to disrupt the cytoplasmic... 

The recovery of intracellular proteins involves distinct cell disruption procedures, depending on the cell characteristics. For the processing of animal cells, which do not have a cellular wall, mild and moderate techniques are commonly used. Mild techniques include cell lysis by enzymatic digestion, chemical solubilization or autolysis and the use of manual homogenizers and grinders, whereas the moderate techniques involve blade homogenizers and abrasive grinding. 

The overall effect of bacteriophage contaminations is influenced by several factors related to the characteristics of the phage itself as well as the timing of infection relative to the stage of the fermentation process. Consequently, independent infections even with the same phage can result in different outcomes. Thus, minor contaminations can only result in extended fermentation times and decreased solvent yield, whereas more severe infections can lead to complete cessation of the fermentation and/or nearly complete cell lysis within hours. 

Because of its physiological importance, many experimental studies were done on the reaction of lysis of bacterial cell walk (Imoto et al., 1972). Most of these studies show that, in contrast to the reaction with oligosaccharides, the lytic activity of lysozyme presents a number of peculiar characteristics which we can summarize as follows. 

The red blood cell has no mitochondria and is totally dependent on anaerobic glycolysis for ATP. In pyruvate kinase deficiency, the decrease in ATP causes the erythrocyte to lose its characteristic biconcave shape and signals its destruction in the spleen. In addition, decreased ion pumping by Na /K -ATPase results in loss of ion balance and causes osmotic fragility, leading to swelling and lysis. 

Figure 4.1 The comet assay. A single-cell suspension is embedded in agarose on a slide. Cells are then subject to lysis followed by electrophoresis. If present, damaged DNA migrates out of the nucleoid structure during electrophoresis to producing a characteristic comet shape. Double-strand breaks are revealed under neutral conditions, whereas alkali conditions additionally show single-strand breaks and alkali labile sites. Image analysis of stained DNA is used to quantitate the amount of damaged DNA in the comet tail.

The polyvalency of IgM causes it to bind more firmly to an antigen than either a univalent or bivalent antibody. In this respect, a single molecule of IgM can cause lysis of a cell. Furthermore, the joining chain (J) has been detected in polymeric IgM and IgA, but not in the other immunoglobulins. About 10% of the IgM in external secretions has the secretory component attached. One wonders whether these characteristics of the IglNI are responsible for its take-over role in the gut, when there is a defective synthesis of IgA as in celiac or in Crohn s disease or in ulcerative colitis. 

The antibody-dependent lysis of tumor cells by PMNs exhibited some of the characteristics of damage mediated by products of the burst in the presence of tumor cells there was increased consumption of O2, increased formation of O and activation of the hexose monosphosphate shunt However, although a reduction in the concentration of O2 in the medium inhibited lysis neither catalase nor superoxide dismutase inhibited. The lack of effect on these enzymes was attributed to their inability to interpose themselves between the plasma membranes of the PMN and its target. Similar conclusions were reached by Clark, and Klebanoff whose data incriminated the products of the burst by the reduced killing of tumor cells by PMNs from patients with chronic granulomatous disease. Myeloperoxidase, however, appeared not to he required since neither azide or cyanide inhibited and killing by PMNs from patients with inherited deficiency of myeloperoxidase was normal. 

Anatomy of the abscission zone at the base of mature fruits has been investigated in apples (10), cherries (11), citrus (12), and olives (13) and has been discussed as related to mechanical fruit removal (2, 14), The histochemistry of the separation layer of mature fruit is very similar to that of leaves of citrus (15) and bean (16,17), The actual separation occurs through one or more processes in the separation zone (a) a weakening of the cementing ability of the middle lamella between cells, and (b) a softening of the entire cells (17), In some plants, the abscission zone is structurally differentiated as a layer of compact cells or as a zone of localized cell division in other species, abscission may occur across a transect of cells which show little or no visible diflFerentiation (18). Thus, major components of the separation process involve the dissolution of middle lamella and lysis of cell walls or entire cells in the separation zone, but this is not necessarily associated with distinctive morphological characteristics (19). 

NOS products of neurons, epithelial cells and other cells in the lung have both bronchodilator and inflammatory properties (Gaston etal., 1994b) the specific nature of this bioactivity depends on the chemical characteristics of the functional products in the specific microenvironment under consideration. For example, NO is capable of complexing with and affecting the activity of a variety of metalloproteins and enzymes, such as guanylyl cyclase and ribonucleotide reductase (Nathan, 1992 Stamler et al., 1992). NO can also complex with superoxide anion to form peroxynitrite, which has a cytotoxic immune effector role (Radi etal., 1991 Stamler etal., 1992). Furthermore, NO can form iron nitrosyl complexes, which are the putative intracellular macrophage products of iNOS responsible for lysis of intracellular parasites (Hibbs... 

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