Triggered activity

A cell may generate oscillating afterpotentials which reach the threshold for activation of the Na+ channel (triggered activity). 

Carlisle RC, Etrych T, Briggs SS, Preece JA, Ulbrich K, Seymour LW (2004) Polymer-coated polyethylenimine/DNA complexes designed for triggered activation by intracellular reduction. J Gene Med 6 337-344... 

A second family of MAPKs is referred to as stress-activated protein kinases (SAPKs) [3,14,15]. This includes JNKs, or Jun kinases, named originally for their phosphorylation of the transcription factor c-Jun. SAPKs were first identified in peripheral tissues on the basis of their activation in response to cellular forms of stress, which include X-ray irradiation and osmotic stress. More recently, they have been demonstrated to be activated in brain by several cytokines as well as by synaptic activity [16]. As shown in Figure 23-3, SAPKs are activated by SAPK kinases (SEKs), which are in turn activated by SEK kinases. The Ras-like small G proteins implicated in SEK kinase activation are Rac and Cdc-42. In this case, it appears that Rac/Cdc-42 triggers activation of SEK kinase by stimulating its phosphorylation by still another protein kinase termed p21-activated kinase (PAK). Thus, PAK can be considered a MAPK kinase kinase kinase, which is analogous to the cascade of protein kinases found in yeast (Fig. 23-4). 

Premature ventricular complexes (PVCs) are common ventricular rhythm disturbances that occur in patients with or without heart disease and may be elicited experimentally by abnormal automaticity, triggered activity, or reentrant mechanisms. 

The cluster of aromatic residues in TM6 composed of residues at positions 6.52/6.48/6.44 on a continuous face of the TM6 helix (53), and their mutual orientation that appears to trigger activation (5,8,38) and... 

Stabilize skeletal matter, muscle and nerve triggering, activation of kinases, catalysis... 

Fig. 5.7. General principle of densen-sitization of G-protein-coupled receptors. Desensitization of a hormone-bound receptors can take place by two principle routes, schematically represented in the figure. A suppressing influence may be exerted on the receptor system via proteins (X) of a signal chain, triggering activation of the signal chain. Receptor systems may also mutually influence one another in that a signal protein X formed in one signal chain mediates the densensitiza-tion of another receptor system R, and vice versa.

Upon recruitment by FADD, caspase 8 oligomerizes, triggering activation by selfcleavage. Caspase 8 then proteolytically activates downstream effector caspases, such as caspase 9, and commits the cell to death. 

Pogwizd SM, Onufer JR, Kramer JB, Sobel BE, Corr PB Induction of delayed afterdepolarisations and triggered activity in canine Purkinje fibers by lysophosphatidylglycerides. Circ Res 1986 59 416-426. 

The carboxyl terminus of the Ga-subunit is the latch for triggered activation of heterotrimeric G proteins. Mol. Pharmacol. 69, 397-405. 

Nanoff, C., Koppensteiner, R., Yang, Q., Fuerst, E., Ahom, H., and Freissmuth, M. (2006). The carboxyl terminus of the G alpha-subunit is the latch for triggered activation of heterotrimeric G proteins. Mol. Pharmacol. 69, 397-405. 

Andresen TL, Jensen SS, Kaasgaard T, Jorgensen K. Triggered activation and release of liposomal prodmgs and drugs in cancer tissue by secretory phospholipase A2. Curr Drug Deliv. 2005 2 353-362. 

Winslow, R., Varghese, A., Noble, D., Ad-lakha, C. and Hoythya, A. Generation and propagation of triggered activity induced by spatially localised Na-K pump inhibition in atrial network models. Proceedings of the Royal Society B 1993, 254 55-61. 

Increased sympathetic activity Baroreceptors sense a decrease in blood pressure, and trigger activation of p-adrenergic receptors in the heart. This results in an increase in heart rate and a greater force of contraction of the heart muscle (Figure 16.4). In addition, vasoconstriction (ai-mediated) enhances venous return and increases cardiac preload. These compensatory responses increase the work of the heart and, therefore, can contribute to the further decline in cardiac function. 

Armour MR, Clark AG, Hadley LM, Williamson LM Recombinant human IgG molecules lacking Fc gamma receptor I binding and monocyte triggering activities, Eur J Immunol 1999 29 2613-24. 

In some facilities, the major emergency alarm is a steady blast on the facility steam whistle. Others use sirens or special bells. Whatever is chosen, the alarm must reach everyone on the site, triggering activation of the facility ERP and the initiation of a head-count procedure. 

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