In recombination

Product formation kinetics in mammalian cells has been studied extensively for hybridomas. Most monoclonal antibodies are produced at an enhanced rate during the Gq phase of the cell cycle (8—10). A model for antibody production based on this cell cycle dependence and traditional Monod kinetics for cell growth has been proposed (11). However, it is not clear if this cell cycle dependence carries over to recombinant CHO cells. In fact it has been reported that dihydrofolate reductase, the gene for which is co-amplified with the gene for the recombinant protein in CHO cells, synthesis is associated with the S phase of the cell cycle (12). Hence it is possible that the product formation kinetics in recombinant CHO cells is different from that of hybridomas. 

Recent work with multi-layer polymer LEDs has achieved impressive results and highlights the importance of multi-layer structures [46]. Single-layer, two-layer and three-layer devices were fabricated using a soluble PPV-based polymer as the luminescent layer. The external quantum efficiencies of the single-layer, two-layer, and three-layer devices were 0.08%, 0.55%, and 1%, respectively, with luminous efficiencies of about 0.5 hn/W, 3 lm/W, and 6 lm/W. These results clearly demonstrate improvement in the recombination current because of the increase in quantum efficiency. The corresponding increase in luminous efficiency demonstrates that the improvement in recombination efficiency was achieved without a significant increase in the operating bias. 

A Bacterial Artificial Chromosome (BAC) is a vector that allows the propagation of larger exogenous DNA fragments, up to several hundred kb. BACs are propagated in recombination-deficient strains of E. coli. They are more stable and easier to handle than yeast artificial chromosomes (YACs). 

Neurosteroids prolong the mean open time of recombinant GABAa receptor channels. Whereas, at least in recombinant systems, the identity of the a and (3 subunits has little or no effect on neurosteroid action, substitution of the y subunit by a 8 subunit suppresses the GABA-modulatory activity of the neurosteroids. 

Preferentially inhibits cAMP formation Preferentially inhibits cAMP formation Preferentially inhibits cAMP formation Preferentially inhibits cAMP formation (in recombinant system). Preferentially inhibits cAMP formation (in recombinant system). 

Increases inwardly rectifying K+ current, PLC activation with increased IPs and elevated [Ca2+]j observed in recombinant systems PLC activation with increased IPs and elevated [Ca2+]j to observed in recombinant systems. PLC activation with increased IPs and elevated [Ca2+]j observed in recombinant systems. ... 

Effector Gq/11 Preferentially increases Pi hydrolysis and elevates [Ca2+]j Gq/n Preferentially increases Pi hydrolysis and elevates [Ca2+]j (in recombinant systems) Gq/nPreferentially increases Pi hydrolysis and elevates [Ca2+], Intrinsic ligandgated ion channel GsPreferentially increases cAMP formation. 

Two NKxr splice variants have been identified (Table 3). A NKxr splice variant having a very short C-terminal intracellular tail (7 instead of 96 amino acids), which has been expressed and characterized in recombinant systems (Fig. 1), was found to be expressed at higher level than the long isoform in breast cancer cells. As compared to the long receptor, the short NKxr isoform is less subjected to desensitization and internalization... 

On the molecular level, all TAARs for which ligands are available, couple to Gas, at least in recombinant systems. Links to other signaling pathways as well as potential heterodimerization within the TAAR family or with other GPCRs have so far not been observed. All TAAR genes have a very similar size of about 1 kb, and posttranslational modification and subcellular trafficking of the receptors are both not well understood. 

Fluorescence Methods for the Analysis of Nucleic Acids in Recombinant Biological Products... 

Regulatory agencies currently set stringent standards on the quantities of nucleic acids allowed in recombinant biological products. In the pharmaceutical industry these requirements necessitate the quantification of trace amounts of nucleic acids in the presence of large quantities of protein and other excipients. Flourescence methods offer advantages for such analyses, but also have limitations. The use of a variety of fluorescent dyes and techniques is described here, and practical examples of such use are presented. 

Abstract In 2007, the world celebrated the 50th anniversary of the discovery of interferon (IFN) by Isaacs and Lindemnann. Subsequently, the IFN-a gene was cloned, fully sequenced and IFN-a was produced in recombinant form. Recombinant IFN-a is now used as the basis for treatment of chronic hepatitis C virus infection and can also be used to treat certain forms of chronic hepatitis B virus infections. IFNs have also been used in other viral infections, although with less success. The antiviral mechanisms of IFNs are reviewed in this chapter as well as the utility of IFNs in the treatment of persistent viral infections. 

Hertogs K, de Bethune MP, Miller V, Ivens T, Schel P, Van Cauwenberge A, Van Den Eynde C, Van Gerwen V, Azijn H, Van Houtte M, Peelers F, Staszewski S, Conant M, Bloor S, Kemp S, Larder B, Pauwels R (1998) A rapid method for simultaneous detection of phenotypic resistance to inhibitors of protease and reverse transcriptase in recombinant human immunodeficiency virus type 1 isolates from patients treated with antiretroviral drugs. Antimicrob Agents Chemother 42 269-276... 

Table 40-3. Some of the enzymes used in recombinant DNA research. ...

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