Specificity enhancement

Whiting, J., Marshall, H., Cook, M., Krumlauf, R., Rigby, P., Stott, D., and Allemann, R. K. (1991). Multiple spatially specific enhancers are required to reconstruct the pattern of Hox-2.6 gene expression. Genes Dev. 5 2048-2059. 

Libermann, T. A., Lenardo, M., and Baltimore, D. (1990). Involvement of a second lymphoid-specific enhancer element in the regulation of immunoglobulin heavy-chain gene expression. Mol. Cell. Biol. 10 3155-3162. 

Ponnazhagan and Kwon (1992) reported a putative tissue-specific ds-element (TE-1) located at-236 bp of the mouse tyrosinase promoter. They partially purified a TE-1 binding protein (approximately 49 kDa in size), but tissue specificity remains to be confirmed by a more detailed analysis. For the human tyrosinase promoter, Shibata et al. (1992) identified a 200-bp pigment cell-specific enhancer, located between -2.0 and -1.8 kb. A minimum core sequence of 39 bp was shown to be sufficient to confer the specific activity, although other regions (not identified so far) within the 200-bp fragment are required for more efficient expression in melanoma cells (Shibata et al., 1992). 

GanB, R., Montoliu, L Monaghan, A. P., and Schiitz, G. (1994c). Acell-specific enhancer far upstream of the mouse tyrosinase gene confers high level and copy number-related expression in transgenic mice. EMBO J. 13 3083-3093. 

The importance of adenosine deaminase in the duration and intensity of sleep in humans has been noted recently (Retey et al. 2005). Animal studies suggest that sleep needs are genetically controlled, and this also seems to apply in humans. Probably, a genetic variant of adenosine deaminase, which is associated with the reduced metabolism of adenosine to inosine, specifically enhances deep sleep and slow wave activity during sleep. Thus low activity of the catabolic enzyme for adenosine results in elevated adenosine, and deep sleep. In contrast, insomnia patients could have a distinct polymorphism of more active adenosine deaminase resulting in less adenosine accumulation, insomnia, and a low threshold for anxiety. This could also explain interindividual differences in anxiety symptoms after caffeine intake in healthy volunteers. This could affect the EEG during sleep and wakefulness in a non-state-specific manner. 

Schnedl, W. J., et al. STZ transport and cytotoxicity. Specific enhancement in GLUT2-expressing cells. Diabetes 1994, 43, 1326-1333. 

Matthay, K.K., Heath, T.D., and Papahadjopoulos, D. (1984) Specific enhancement of drug delivery to AKR lymphoma by antibody-targeted small unilamellar vesicles. Cancer Res. 44, 1880-1886. 

Positive regulators (enhancers) Turn on transcription when a specific effector protein binds to a specific enhancer sequence in the DNA. 

A drug that specifically enhances metabolically the activity of brain dopamine is... 

Semke E., Distel H. and Hudson, R. (1995) Specific enhancement of olfactory receptor sensitivity associated with foetal learning of food odours in the rabbit. Naturwissenschaften 82, 148-149. 

Electrospray ionization will often produce ions that are fully coordinated, stable, and nonreactive in the gas phase. These ions may be probed by removal of ligands to form coordinatively unsaturated ions that are generally reactive. The chemical activity of metal cluster ions differs markedly and often shows size specific enhanced reactivity or lack of reactivity. Silver cluster ions Ag are fairly inert similar to Ag+. Platinum cluster ions PL are quite reactive similar to Pt+. Often, large cluster ions only appear to react with one donor molecule such as benzene this may be due to low concentrations of reactants or short reaction times. Similar clusters may react with a larger number of smaller molecules, and so until more information is available, rules for the coordination behavior of metal clusters are as yet not available. 

Song, H. K. and Egk, M. J. Structural basis of degradation signal recognition by SspB, a specificity-enhancing factor for the ClpXP proteolytic machine. Mol Cell 2003, 12, 75-86. 

Pauwels, R., van der Straeten, M., Platteau, B., and Bazin, H. (1983) The non-specific enhancement of allergy. In vivo effects of Bordetella pertussis vaccine on IgE synthesis. Allergy. 38, 239-246. 

Precursor therapy as a means of increasing dopaminergic transmissions is limited to L-tyrosine and L-dopa. Although under basal conditions the exogenous administration of tyrosine leads to specific enhancement of noradrenergic transmission, it can enhance dopaminergic transmission in conditions of DA deficiency [Kapur and Mann 1992). Only one adequately controlled clinical trial has been reported, in which 65 patients with major depression were randomly selected to treatment for 4 weeks with oral L-tyrosine 100 mg/kg/day, imipramine 2.5 mg/kg/day, or placebo [Gelenberg et al. 1990). Tyrosine increased and imipramine decreased excretion of the main metabolite of NA, but no evidence was found that tyrosine had antidepressant activity in contrast with imipramine. 

So why would a broad substrate specificity enhance the generation and retention of chemical diversity ... 

Cottrell, S., Oliver, K., Lake, B.G. Powell, C.J. (1996) Strain-specific enhancement or inhibition of coumarin hepatotoxicity in mice following pretreatment with two different liver enzyme-inducing agents. Fundam. appl. Toxicol, 34, 47-55 Cox, D., O Kennedy, R. Thornes, R.D. (1989) The rarity of liver toxicity inpatients treated with coumarin (1,2-benzopyrone). Hum. exp. Toxicol, 8, 501-506 Dexeus, E.H., Logothetis, C.J., Sella, A., Fitz, K., Amato, R., Reuben, J.M. Dozier, N. (1990) Phase II study of coumarin and cimetidine in patients with metastatic renal cell carcinoma. J. din. Oncol, 8, 325-329... 

Adjuvant In immunology, a substance injected with antigens (usually mixed with them but sometimes given prior to or following the antigen) which non-specifically enhances or modifies the immune response to that antigen. 

The only aggregate enhanced in D20 is the IIS species. This specific enhancement is additional support for our previous suggestion that the IIS aggregate is favored under conditions that are associated with a hydrophobic force mechanism, and the 7S is not. It appears then that comparative studies of aggregation phenomena in H20 and D20 are a convenient method for indicating aggregation processes favored by hydrophobic forces. 

Chandler, V. L., B. A. Maler, and K. R. Yamamoto, DNA sequences bound specifically by glucocorticoid receptor in vitro render a heterologous promoter responsive in vivo A steroid specific enhancer. Cell 33 489-499, 1983. 

Early indications from the use of reboxetine show that its efficacy is at least comparable to that of the tricyclic antidepressants and the SSRIs. In addition, reboxetine may specifically enhance social functioning, perhaps by converting apathetic responders into full remitters. Furthermore, reboxetine may be useful for severe depression, for depression unresponsive to other antidepressants, and as an adjunct to serotonergic antidepressants when dual neurotransmitter mechanisms are necessary to treat the most difficult cases. 

Meyer, K.B. Neuberger, M.S. (1989). The immunoglobulin k locus contains a second, stronger B-cell-specific enhancer which is located downstream of the constant region. EMBO J. 8, 1959-1964. 

Picard, D. Schaffner, W. (1984). A lymphocyte-specific enhancer in the mouse immunoglobulin k gene. Nature 307, 80-82. 

Li, S., MacLaughlin, F.C., Fewell, J.G., Gondo, M., Wang, J., Nicol, F. et al. (2001) Muscle-specific enhancement of gene expression by incorporation of the SV40 enhancer in the expression plasmid. Gene Ther., 8, 494 197. 

---