Selective targeting

Interplanar Spacings. Diffractometer alignment procedures require the use of a well-prepared polycrystalline specimen. Two standard samples found to be suitable are silicon and a-quartz (including Novaculite). The 26 values of several of the most intense reflections for these materials are listed in Table 7.6 (Tables of Interplanar Spacings d vs. Diffraction Angle 26 for Selected Targets, Picker Nuclear, White Plains, N.Y., 1966). To convert to d for Ka or to d for Ka2, multiply the tabulated d value (Table 7.6) for Ka by the factor given below ... 

Camptothecin is a plant alkaloid that selectively targets topoisomerase I (Topi). It produces DNA damage leading to the destruction of eukaryotic cells. Because... 

Table 1 Biological activities of ER ligands in selected target tissues...

Chiarantini L., Cerasi A., Eraternale A., Andreoni E., Scari S., Giovine M., Clavarino E., Magnani M. Inhibition of macrophage iNOS by selective targeting of antisense PNA. Biochemistry 2002 41 8471-8477. 

Pissuwan, D., Valenzuela, S., Miller, C.M. and Cortie, M.B. (2007) A golden bullet Selective targeting of Toxoplasma gondii tachyzoites using antibody-functionalised... 

In order to develop compounds that can selectively target duplex RNA, Sinha et al. [ 194] studied the interaction of berberine with two different conformations of poly(rC) poly(rG) structures. Poly(rC) poly(rG) has been shown [15,215] to exist in two conformations depending on the pH of the solution, the A-form at physiological pH and the protonated form at pH 4.3. These two conformations have been characterized to have clearly defined but distinctly different circular dichroic and absorption spectral characteristics. Both the A-form and the protonated form of the RNA induced moderate hypochromic change and bathochromic shifts in the absorption maxima peaks at 344 nm and 420 nm of the alkaloid with three isosbestic points centered around 357,382 and 448 nm. Binding of berberine to both forms enhanced the fluorescence intensity, which was higher with the protonated form than with the A-from, suggesting clear differences in the nature of orientation... 

A field test was conducted by spraying a commercial oil spill-dispersant (Corexit 9527) from aircraft [696]. Test objectives were to determine the efficiency of delivering the dispersant to a selected target using a large aircraft and to compare various measurement systems for droplet size and spray pattern distribution. The results indicated that aerial flights up to 46 m can produce droplet sizes and swath widths that would be operationally effective for an oil spill. 

The chemical and biological implications of compounds that support reversible but covalent processes are often lost in a common assumption that all covalent reactions of DNA are irreversible. Difficulty with reversible reactions is often encountered while attempting to isolate labile products as mentioned above and described more fully in Section 9.2. Yet, reversibility also has the potential to extend the effective lifetime of transient intermediates (Section 9.3.2) and support selective, target-promoted QM... 

External stimuli have also been used to further target liposomes. In one such study magnetite particles were incorporated in radiolabeled liposomes and a magnet positioned over the right kidney of a test animal. The liposomes were selectively targeted to that kidney in concentrations that were viewed as significantly high for relevant clinical applications [66],... 

Antibodies have also been adsorbed or covalently linked to a variety of other carrier systems, such as liposomes [124], erythrocytes [226,227], and microcapsules and nanospheres, to selectively target them to a specific site in the body. 

K. J. Widder and A. E. Senyei, Magnetic microsphere A vehicle for selective targeting of organs, in Methods of Drug Delivery (G. M. Ihler, ed.), Pergamon Press, New York, 1986, p. 39. 

An interesting imaging probe Id that can selectively target bacteria was recently reported by Smith et al. [31] also based on a heptamethine chromophore. The probe is composed of a bacterial affinity group, which is a synthetic zinc (II) coordination complex that targets the anionic surfaces of bacterial cells and a near infrared dye. The probe allowed detection of Staphylococcus aureus in a mouse leg infection model using whole animal near-infrared fluorescence imaging. 

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