Poly tract

Poly(ethylene oxide) resins are safely used in numerous pharmaceutical and personal-care appHcations. Poly(ethylene oxide) resins show a low order toxicity in animal studies by all routes of exposure. Because of their high molecular weight, they are poorly adsorbed from the gastrointestinal tract and completely... 

A pH-sensitive gel, poly(AAc), was used as a coating on capsules containing insulin and surfactant. The capsules protected against insulin release in the upper gastrointestinal tract. As the pH increased to 7.5, drug release increased... 

A) tracts, whereas conformation of the probe changed in the presence of an RNA poly(A)tract (alteration on the micropolarity around a pyrenecarboxamide chromo-phore caused by hybridization with the targeted RNA) and a much higher fluorescence was observed. 

Fluorescence measurement using this probe does not require a fluorescence quencher or washing process to suppress the fluorescence emission from nonbinding probes and nonspecific binding probes, which would be advantageous for the detection of mRNAs with poly(A) tracts in cells. 

Tanaka K, Okamoto A (2008) Design of a pyrene-containing fluorescence probe for labelling of RNA poly(A) tracts. Bioorg Med Chem 16 400-404... 

Translational efficiency of luciferase mRNAs lacking a poly(A) tract and capped with anti reverse cap analogs in a RRL system. The relative translational efficiency was calculated as described in the text. Translational efficiency of luciferase mRNAs containing 60-nt poly (A) tract and capped with anti reverse cap analogs in MM3MG cells. Luciferase activity was normalized by the amount of luciferase RNA in the cells. Relative translational efficiency was calculated as noted previously. 

Degradation of 5 -terminal sequences in luciferase mRNA containing 60-nt poly(A) tract and capped with the indicated anti reverse cap analogs. The mRNAs half-lives were determined by real time PCR with primers directed against the 5 -end of luciferase mRNA as described in the text. 

The nature of the cap structure can also influence mRNA stability. The stability of mRNA capped with different ARCAs is determined in MM3MG cells that are electroporated with luciferase mRNAs containing a 60-nt poly(A) tract and different cap analogs. The experiment is done... 

The failure in increasing residence time of mucoadhesive systems in the human intestinal tract has led scientists to the evaluation of multifunctional mucoadhesive polymers. Research in the area of mucoadhesive drug delivery systems has shed light on other properties of some of the mucoadhesive polymers. One important class of mucoadhesive polymers, poly(acrylic acid) derivatives, has been identified as potent inhibitors of proteolytic enzymes [72-74]. The interaction between various types of mucoadhesive polymers and epithelial cells has a direct influence on the permeability of mucosal epithelia by means of changing the gating properties of the tight jrmctions. More than being only adhesives, some mucoadhesive polymers can therefore be considered as a novel class of multifunctional macromolecules with a number of desirable properties for their use as delivery adjuvants [72,75]. 

Akiyama, Y., Nagahara, N., Kashihara, T., Hirai, S., and Toguchi, H., In vitro and in vivo evaluation of mucoadhesive microspheres prepared for the gastrointestinal tract using polyglycerol esters of fatty acids and a poly(acrylic acid) derivative, Pharm. Res., 12 397-405... 

Vann, W.F. and Jann, K. (1979) Structure and serological specificity of the K13 poly-antigenic polysaccharide (K13 antigen) of urinary tract infective E.coli. Infect. Immun. 25 85-92... 

Most mature mRNAs have a post-transcriptionally added poly (A) tract at their 3 end (Wahle and Ruegsegger, 1999). Usually preceding the poly (A) addition site is a sequence transcribed from the sequence AATAAA on the DNA. This sequence, the so-called poly (A) signal, is the most conserved recognition element in eukaryotes. This sequence motif directs the cleavage of primary transcripts... 

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