Rescue effect

In our recent study of reaction kinetics, we observed an unusual phenomenon when we analyzed the activity of a hammerhead ribozyme as a function of the concentration of Na ions on a background of a low concentration of either Mn or Mg ions [82]. At lower concentrations of Na ions, Na ions had an inhibitory effect on ribozyme activity, whereas at higher concentrations, Na ions had a rescue effect. We propose that these observations can be explained if we accept the existence of two kinds of metal-binding site that have different affinities. Our data also support the two-phase folding theory [77-80, Fig. 7], in which divalent metal ions in the ri-bozyme-substrate complex have lower and higher affinities, as proposed by Lilley and coworkers on the basis of their observations of ribozyme complexes in the ground state. 

Analyses of both the thio effect and of soft acid rescue effects, such as the rescue effects of Cd, Mn, and Zn ions, have contributed significant-... 

With regard to the protective effects observed under in vivo ischemia, the laser-doppler investigation showing no flow modification after treatment with MS rules out that rheological modifications are involved in the neuroprotective action of the drug. This is also confirmed in in vitro experiments where an in situ rescuing effect of this compound mediated by catalase was demonstrated. 

Pittman SW, and Frei E. 1977. Weekly methotrexate-calcium leucovorin rescue effect ofalkalinization on nephrotoxicity pharmacokinetics in the CNS, and use in CNS non Elodgkin s lymphoma. CancerTreat Rep. 61 695-701. 

Classic metapopulations result from low to intermediate migration between habitat patches. Not all potential habitats necessarily contain populations. Migration between patches affects the dynamics of local populations, even including recolonization following extinction. If sufficient dispersal between patches exists, then a "rescue effect" can prevent local extinctions. Persistence of a metapopulation requires migration rates between patches, which are sufficient enough to offset local extinction rates. 

In this section, we report MD simulations of the native and mutated full-length HHRs in the reactant state and in an activated precursor state (C17 02 deproto-nated). Each simulation has a production trajectory of 60 ns. There exists a wealth of experimental mutational effect data, and simulations of key mutations can offer a detailed rationalization of these effects in terms of structure and dynamics, forge a closer connection between theory and experiment, and provide deeper insight into mechanism. Simulations were performed with the C3U, G8A, and G8I single mutants, and a C3U/G8A double mutant that exhibits an experimental rescue effect [73]. 

FIGURE 7.5 Decline of photoreceptors in the RCS retina between 15 and 60 days of life and the effects of MIF and ACTH-peptide 4-9 injected into the vitreous body. The rescue effects are significant in both cases. The counts were obtained at 60 days after birth (from... 

Cell death of spinal motoneurons in the chick embryo following deafferentation rescue effects of tissue extracts, soluble proteins, and neurotrophic agents. J. Neurosci. 14 1619-1 MO. 

Katoh, S., Mitsui, Y., Kitani, K., and Suzuki, T., The rescuing effect of nerve growth factor is the result of up-regulation of bcl-2 in hyperoxia-induced apoptosis of a subclone of pheochromocytoma cells PC12h, Neurosci. Lett., 232 (2), 71,1997. 

This procedure can be applied to most P2P mixes but is especially effective on the methods to follow. However, in super clean methods, such as the PdCl2 below, where lots of isosafrole is produced, the iso byproduct can interfere with crystal formation. Someone-Who-ls-Not-Strike once found that when an appreciable amount of isosafrole was formed to the detriment of MD-P2P, the oil screwed up the crystal matrix disallowing it to form. Confused, the chemist tried to rescue the uncrystallized oil from the aqueous solution by extracting out the oil to try other things. But when the solvent hit the solution, the P2P crystallized out. Go figure The... 

Specialty duties are assigned to teams formed for specific tasks or responding to unusual circumstances (e.g., waste characterization, confined-space rescue, asbestos, lead abatement, etc.). These teams are formed, as necessary, on a permanent or temporary basis. In many cases, special training, drills and exercises, and development of safe work plans are needed to prepare team members to conduct work safely and effectively. 

Leukotriene modifiers either inhibit 5-lipoxygenase (zileuton) or competitively antagonize the effects of leukotriene D4 (montelukast and zafirlukast). These agents improve FEV, and decrease asthma symptoms, rescue drug use, and exacerbations due to asthma. Although these agents offer the convenience of oral therapy for asthma, they are significantly less effective than low doses of inhaled corticosteroids.2,33... 

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