Albumin enhancement

Triton X-100 or bovine serum albumin enhances recovery during purification [11]... 

Makara JK, Mor M, Fegley D, Szabo SI, Kathuria S, Astarita G, Duranti A, Tontini A, Tarzia G, Rivara S, Freund TF, Piomelli D (2005) Inhibition of cyclooxygenase-2 potentiates retrograde endocannabinoid effects in hippocampus. Nat Neurosci 7(7) 697-8 Makriyannis A, Guo J, Tian X (2005a) Albumin enhances the diffusion of lipophilic drugs into the membrane bilayer. Life Sci 77(14) 1605—11... 

S. I. Miyatake, S. Tani, F. Feigenbaum, P. Sundaresan, H. Toda, O. Narumi, H. Kikuchi, N. Hashimoto, M. Hangai, R. L. Martuza, and S. D. Rabkin, Hepatoma-specific antitumor activity of an albumin enhancer/promoter regulated herpes simplex virus in vivo, Gene Ther. 6 564 (1999). 

Transgenic mice carrying the u-PA gene linked to the albumin enhancer/promoter exhibit spontaneous intestinal and intraabdominal bleeding directly related to transgene expression in the liver and elevated plasma u-PA levels 50 % die between 3 and 84 h after birth severe hypofibrinogenemia, loss of clotting function. 

Pinkert, C. A., Omitz, D. M., Brinster, R. L., and Palmiter, R. D. (1987) An albumin enhancer located 10 kb upstream functions along with its promoter to direct efficient, liver-specific expression in transgenic mice. Genes Dev. 1, 268-276. 

I-Albumin Enhancement, counts control /xlOO... 

Modification of human serum albumin by o-glucose impaired its antiapoptotic activity for endothelial cells a 50% loss of activity corresponded to about four fiuctosamine residues per protein molecule. In another study, D-fiuctose-albumin enhanced nitric oxide synthase activity and a consequent NO-dependent apoptosis in vascular endothelial cells. " This effect was also attributed to a possible mechanism of hyperglycemia-induced vasculopathy in diabetic patients. In proximal tubular epithelial cells, however, the effect of co-incubated D-fiuctose-albumin was the... 

Simoes, S., Slepushkin, V., Fires, R, Caspar, R., Pedroso, D. L. M., Duzgunes, N. 2000. Human serum albumin enhances DNA transfection by lipoplexes and confers resistance to inhibition by serum. Biochim. Biophys. Acta 1463 459 69. 

The resolution of these columns for protein mixtures, however, was comparably poor. The peak capacity for human serum albumin was near 3 during 20 min gradient elution. Improvement has been reached by covalent binding of PEI (M = 400-600) onto a 330 A silica of 5 pm particle size [38], The peak capacities of ovalbumin and 2a -arid glycoprotein were 30-40 (tgradienl = 20 min). Enhanced peak capacity and resolution probably were due to the more diffuse structure of PEI coupled to silane moieties than that of strictly adsorbed on silica and cross-linked (see Sect, 2.2). Other applications of covalently adsorbed PEI are discussed in Sect. 4.1. 

Hormone response elements (for steroids, T3, retinoic acid, peptides, etc) act as—or in conjunction with— enhancers or silencers (Chapter 43). Other processes that enhance or silence gene expression—such as the response to heat shock, heavy metals (Cd and Zn +), and some toxic chemicals (eg, dioxin)—are mediated through specific regulatory elements. Tissue-specific expression of genes (eg, the albumin gene in liver, the hemoglobin gene in reticulocytes) is also mediated by specific DNA sequences. 

Copper is an essential trace element. It is required in the diet because it is the metal cofactor for a variety of enzymes (see Table 50—5). Copper accepts and donates electrons and is involved in reactions involving dismu-tation, hydroxylation, and oxygenation. However, excess copper can cause problems because it can oxidize proteins and hpids, bind to nucleic acids, and enhance the production of free radicals. It is thus important to have mechanisms that will maintain the amount of copper in the body within normal hmits. The body of the normal adult contains about 100 mg of copper, located mostly in bone, liver, kidney, and muscle. The daily intake of copper is about 2—A mg, with about 50% being absorbed in the stomach and upper small intestine and the remainder excreted in the feces. Copper is carried to the liver bound to albumin, taken up by liver cells, and part of it is excreted in the bile. Copper also leaves the liver attached to ceruloplasmin, which is synthesized in that organ. 

Formulation strategies for stabilization of proteins commonly include additives such as other proteins (e.g., serum albumin), amino acids, and surfactants to minimize adsorption to surfaces. Modification of protein structure to enhance stability by genetic engineering may also be feasible, as well as chemical modification such as formation of a conjugate with polyethylene glycol. 

Squaraine dyes 10b, 39a, 39b, 41a, 41c, 41d, and 41e were used to measure different proteins such as BSA, HSA, ovalbumin, avidin from hen egg white, lysozyme, and trypsin (Fig. 12) [58]. It is difficult to predict correlations between the dyes structures and the affinity or sensitivity of the dyes for different proteins. All squaraine probes exhibit considerable fluorescence increases in the presence of BSA. Dicyanomethylene-squaraine 41c is the brightest fluorescent probe and demonstrates the most pronounced intensity increase (up to 190 times) in presence of BSA. At the same time, the fluorescent response of the dyes 10b, 39a, 39b, 41a, 41c, 41d, and 41e in presence of other albumins (HSA and ovalbumin) is, in general, significantly lower (intensity increases up to 24 times). Dicyanomethylene-squaraine 41a and amino-squaraines 39a and 39b are the most sensitive probes for ovalbumin. Dyes 41d, 10b, and 41e containing an A-carboxyalky I -group demonstrate sufficient enhancement (up to 16 times) in the presence of avidin. Nevertheless, the presence of hydrolases like lysozyme or trypsin has only minor effects on the fluorescence intensity of squaraine dyes. 

Nanosized objects perform various functions in the biomedical field. In the human body, nanosized particulate substances behave very differently from larger particles. In 1986, Maeda et al. found that the stained albumin, having a size of several nanometers, naturally accumulates in the region of cancerous tissues, which is now well known as the enhanced permeability and retention (EPR) effect. Many studies in the field of nanoparticles are based on this finding. Another application of nanoparticles is the delivery system using various polyplexes that are composed of carrier molecules and plasmid DNA or nucleic acid drugs such as antisenses and siRNA. In addition, nanofibers are mainly used for biodegradable scaffolds in tissue... 

Some dmgs are bound to plasma proteins in blood. Plasma protein levels in blood may be decreased in the elderly, but this is most often not clinically relevant since a drug s elimination increases when the free, unbound drug concentration is enhanced (Turnheim 1998). The plasma albumin level may however be markedly decreased in elderly suffering from malnutrition or severe disease. For those patients the concentration of the free unbound drug can reach toxic levels (Waiter-Sack and Klotz 1996). 

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