Lysis activity

Fig. 1. Effect of HyHEL-10 on M. lysodeikticus lysis activity of chicken lysozyme at 0.1 nM concentration using the competitive inhibition enzyme assay described in the text (a) Raw data with varying concentrations of antibody and the substrate-only control, (b) Plot of antibody concentration versus decrease in absorbance at 450 nm per minute at 0.1 nAf enzyme (unconected for substrate-only control).

Since lipid (lipoprotein) inhibit lysis, agents that lower lipid levels have a normalizing effect on decreased fibrinolysis activity due to elevated lipids. Even the removal of normal lipid content from plasma with chloroform increases lysis activity. Vasoactive agents have previously been reported61 to stimulate activator release resulting in enhanced lysis activity of short duration. 

The normal tissue lysis activators are proteins. One such activator from the kidney is urokinase. This enzyme has not been found systemically, but only in the kidney and urine. It directly activates plasminogen to plasmin by hydrolysis of a small peptide from the plasminogen molecule. Other known enzymatic activators are streptokinase and brinase, which have been discussed elsewhere.82>83 Urokinase can be isolated from urine in small amounts. This has made it a very expensive material. Abbott Laboratories has developed a tissue culture technique in which kidney cells are grown under exacting conditions and urokinase is isolated.84 Recently Abbott Laboratories made a request to the FDA for a license to sell this form of urokinase called Abbokinase . This process should increase the availability of urokinase and decrease its cost. 

There are many synthetic chemicals that have been reported to increase lysis activity, chloroform being one of the earliest reported.68 More recently acid anti-inflammatory,87 antidiabetogenic,BS vasoactive,81 and diuretic agents,86 and anabolic steroids60 have been reported to have some effect on the lysis system. Even whiskey (alcohol) has been reported to enhance lysis.61 Hedner, et al.62 reported that ethyloestrend (8 mg/ day) increased spontaneous lysis in 45 patients with deep venous thrombosis and pulmonary embolism after 3 months of treatment. Euphillin (amino-phylline) was reported to increase abnormally low fibrinolysis in human patients and in rabbits with venous thrombosis.09 When 40 mg of furose-mide was injected i.v. into 33 healthy people, the euglobulin lysis time was shortened.64 Since this activation was not found in patients with uremia and nephrectomy, an intact renal system appears necessary. 

Prourokinase is a single-chain, urokinase-like plasminogen activator of 411 amino acids that displays clot-lysis activity yet does not interfere with hemostasis (131). It is nonimmunogenic and has a more favorable dose-related safety and efficacy profile than both urokinase and... 

Antibodies can damage parasites directly, induce lysis, activate complement, agglutinate extracellular forms, stimulate antibody-dependent cellular cytotoxicity, and block their entry into their host cells. IgM, IgG, and IgA antibody isotypes are involved in these reactions. The isotype specificity not only depends on in which host compartment the parasite is residing (e.g., respiratory tree, GI tract, GU tract [IgA], bloodstream, lymphoid tissue [IgM, IgG]) but also on the antigens expressed during the different developmental stages and their chronicity. 

Chauthaiwale J, Rao M (1994) Production and purification of extracellular D-xylose isomerase from an alkaliphilic, thermophilic Bacillus sp. Appl Environ Microbiol 60(12) 4495-4499 Chen JP, Chen YC (1996) Improvement of cell lysis activity of immobilized lysozyme with reversibly soluble-insoluble polymer as carrier. Biotechnol Tech 10(10) 749-754 Chen R (2001) Enzyme engineering rational design versus directed evolution. TIBTECH 19(1) 13-14... 

Neutron Activation Ana.lysis, A measured sample activated by neutron bombardment emits gamma rays that are used to determine the mercury content by proton-spectmm scanning. Mercury concentrations as low as 0.05 ppb have been determined by this method. 

Cell Disruption Intracellular protein products are present as either soluble, folded proteins or inclusion bodies. Release of folded proteins must be carefully considered. Active proteins are subject to deactivation and denaturation, and thus require the use of gentle conditions. In addition, due consideration must be given to the suspending medium lysis buffers are often optimized to promote protein stability and protect the protein from proteolysis and deactivation. Inclusion bodies, in contrast, are protected by virtue of the protein agglomeration. More stressful conditions are typically employed for their release, which includes going to higher temperatures if necessaiy. For native proteins, gentler methods and temperature control are required. 

Several drugs in current medical use are mechanism-based enzyme inactivators. Eor example, the antibiotic penicillin exerts its effects by covalently reacting with an essential serine residue in the active site of glycoprotein peptidase, an enzyme that acts to cross-link the peptidoglycan chains during synthesis of bacterial cell walls (Eigure 14.17). Once cell wall synthesis is blocked, the bacterial cells are very susceptible to rupture by osmotic lysis, and bacterial growth is halted. 

The observation of dependent variable values (in functional experiments this is cellular response) as they happen (i.e., as the agonist or antagonist binds to the receptor and as the cell responds) is referred to as real time. In contrast, a response chosen at a single point in time is referred to as stop-time experimentation. There are certain experimental formats that must utilize stop-time measurement of responses since the preparation is irreparably altered by the process of measuring response. For example, measurement of gene activation through reporter molecules necessitates lysis of the cell. Therefore, only one... 

Haemostasis is the mechanism activated after damage to the blood vessel wall that ensures that blood loss is restricted. Blood platelets are are activated and adhere to elements on the damaged lumenal surface of the vessel, eventually forming a platelet plug that stops the leakage of blood. Fibrinolytic mechanisms later produce lysis of the platelet mass when repair of the vessel has occurred. 

Helper T2 cells—increase activity of cytotoxic (killer) T cells, which attack the cell directly by altering the cell membrane and causing cell lysis (destruction)... 

Daucus carota Couette viscometer laminar regrowth mitochondrial activity membrane integrity cell lysis (cell number) non-growth (sterile) [57, 69]... 

Nicotiana tabacum Couette-type transitional/turbulent cell lysis (dry weight reduction) mitochondrial activity metabolite secretion non-growth [77]... 

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