Tetracycline, response

Gosen, M., and H. Bujard, Tight control of gene expression in mammalian cells by tetracycline responsive promoters. Proc Natl Acad Sci USA, 1992. 89 5547-51. 

Recently, this latter viral trans-activation system has been modified to a tetracycline-responsive system (Gossen and Bujard, 1992). In vitro, the trans-activation of a luciferase responder gene could be regulated over up to... 

Blaauw et al. [84] adapted a state-of-the-art Tet° system known from gene expression systems in mammalian cell fines (see Part IV, Chapter 1). Plasmid 1 (response plasmid) remains extrachromosomal, and has a hsr selection cassette and a tetracycline-responsive minimal promoter consisting of seven copies of the tetracycline operator sequence (tetO) upstream of an actl5 minimal promoter this is used... 

Weinmann, P., et ah, A chimeric transactivator allows tetracycline-responsive gene expression in whole plants. Plant J, 1994 5(4) 559-569. 

Henriksen JR, Lokke C, Hammero M, Geerts D, Versteeg R, Flaegstad T, et al. Comparison of RNAi efficiency mediated by tetracycline-responsive H1 and U6 promoter variants in mammalian cell lines. Nucleic Acids Res 2007 35 e67. 

Stonge L, Funh PA, Gtuss P. Temporal ctHittol of the ere recombinase in transgenic mice by a tetracycline responsive promoter. Nucl Acids Res 1996 24 3875-3877. 

Dmg distribution into tissue reservoirs depends on the physicochemical properties of the dmg. Tissue reservoirs include fat, bone, and the principal body organs. Access of dmgs to these reservoirs depends on partition coefficient, charge or degree of ionization at physiological pH, and extent of protein binding. Thus, lipophilic molecules accumulate in fat reservoirs and this accumulation can alter considerably both the duration and the concentration—response curves of dmg action. Some dmgs may accumulate selectively in defined tissues, for example, the tetracycline antibiotics in bone (see Antibiotics,tetracyclines). 

It has been known for some time that tetracyclines are accumulated by bacteria and prevent bacterial protein synthesis (Fig. 4). Furthermore, inhibition of protein synthesis is responsible for the bacteriostatic effect (85). Inhibition of protein synthesis results primarily from dismption of codon-anticodon interaction between tRNA and mRNA so that binding of aminoacyl-tRNA to the ribosomal acceptor (A) site is prevented (85). The precise mechanism is not understood. However, inhibition is likely to result from interaction of the tetracyclines with the 30S ribosomal subunit because these antibiotics are known to bind strongly to a single site on the 30S subunit (85). 

Discuss ways to promote an optimal response to therapy, how to manage adverse reactions, and important points to keep in mind when educating patients about the use of a tetracycline, macrolide, or lincosamide. 

The objective of antibiotic treatments is to reduce the density of microbial pathogen in infected udder tissues and thereby improve the capacity of the animal s immune system to deal with the infection. The effect of a successful antibiotic treatment is therefore self-cure of mastitis (Hamann and Kromker, 1999). However, some antibiotics (e.g. tetracycline and gentamycine) may also have negative side effects on the animal s immune response to udder infection, as they have been shown to inhibit/reduce phagocytosis of the animal s own defence cells (Nickerson et al 1986). 

Xenobiotic response in humanized double transgenic mice expressing tetracycline-controlled transactivator and human CYPIBI. Arch Biochem Biophys 395 32-40. 

Sulfacetamide Prednisolone (Blephamide, Others) [AntibiotiC/ Anti-inflammatory] Uses Steroid-responsive inflammatory ocular conditions w/ Infxn or a risk of Infxn Action Antibiotic anti-inflammatory Dose Adults Feds >2 y. Apply oint lower conjunctival sac daily-qid soln 1-3 gtt 2-3 h while awake Caution [C, /-] Sulfonamide sensitivity age <2 mo Disp Oint, susp SE Irritation, burning, blurred vision, brow ache, Stevens-Johnson synd, photosens Interactions T Effects W/ tetracyclines EMS T Risk of photosensitivity Rxns OD Unlikely to cause life-threatening Sxs... 

There is little difference in clinical response among the various tetracyclines The selection of an agent, therefore, is based on tolerance, ease of administration, and cost. The restriction of their use in pregnancy and in patients under the age of 8 years apphes to all preparations. 

L D. Doxycycline is the preferred parenteral tetracycline for the primary state of Lyme disease in adults and children older than 8 years of age. Penicillin V (A) would be ineffective. Erythromycin (B) and clarithromycin (C) also are not effective against Borrelia burgdorferi, the gram-negative anaerobe organism responsible for Lyme disease. 

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