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K M Bradshaw

Publications and source records attributed to K M Bradshaw.

6 recordsLinked to original sources
PubMed1995

11B nuclear magnetic resonance studies of the interaction of borocaptate sodium with serum albumin.

The interaction between borocaptate sodium, Na2B12H11SH (BSH), and three types of serum albumin--bovine, human and dog (BSA, HSA and DSA)--has been investigated quantitatively using 11B NMR. The 11B chemical shifts and relaxation rates of BSH were studied with various concentrations of serum albumin (1-5%, w/v) at 295-310 degrees K. Correction of the longitudinal relaxation rate (R1) due to protein viscosity effects was accomplished. The corrected R1 values were analyzed mathematically using a saturation function and linear regression. The linewidths of 11B resonances, which are related to the spin-spin relaxation rates (R2), were also measured. The binding fractions (P), the number of binding sites (NBS), and the binding constants (Kb) of BSH at various concentrations of the three types of serum albumin (1-5%, w/v) were determined at 295 and 310 degrees K. We speculate that the nature of this interaction may be electrostatic.

Animals↗
PubMed1995

BSH distributions in the canine head and a human patient using 11B MRI.

A 3D projection reconstruction (3DPR) method was used to obtain in vivo 11B images in a large canine brain tumor model and in a human infused with borocaptate sodium (BSH). Studies were performed in dogs with and without gliosarcomas implanted and grown to a size of 2-3 cm. The 3DPR method demonstrates a signal-to-noise ratio (SNR) that allows qualitative kinetic studies of the boron compound in normal and tumor tissue of the head. The measurements indicate initial uptake of the BSH compound in tumor to be less than that in muscle with no uptake in normal brain tissue. Moreover, uptake of BSH in tissue was found to lag the boron concentration in blood with delays that depend on tissue type. In addition, the first human boron images were obtained on a patient who underwent surgical resection and volumetric debulking of a large (7 cm) glioblastoma multiforme. BSH was readily taken up in residual tumor tissue, while diffusion into the resection volume was slower.

Animals↗
PubMed1995

High-performance liquid chromatographic determination of bisacodyl in pharmaceutical dosage forms marketed in Australia.

HPLC methods have been developed for the assay of bisacodyl in various pharmaceutical forms. The extraction procedures are simple and the HPLC conditions separate bisacodyl from its degradation products. The chromatography was performed using a Merck LiChrospher RP-select B column, a mobile phase of 55% acetonitrile/45% 0.05 M KH2PO4 and detection by UV at 214 nm.

Bisacodyl↗
PubMedDate not supplied

Boron-11 imaging with a three-dimensional reconstruction method.

A three-dimensional projection reconstruction technique is described for imaging boron-11 distributions, with potential application to boron neutron capture therapy. The method samples a spherical volume of k space uniformly to obtain a 32 x 32 x 32 matrix with voxel size of 0.42 cm3. A signal-to-noise ratio (S/N) of 3 was obtained in 8.5 minutes in a phantom containing 75 micrograms/mL of boron in borocaptate sodium (BSH). Images were obtained in a dog after cessation of an intravenous infusion of BSH and again 30 minutes later, with a maximum boron S/N of about 12. Boron levels in the brain dropped about 6%-8% and were more diffusely distributed on the images obtained 30 minutes after BSH infusion.

Animals↗