Disease relevance of boron

• PURPOSE/OBJECTIVE: Boron neutron capture therapy (BNCT) is a method of treating high-grade gliomas of the brain that involves incorporating 10B into the tumor using appropriate pharmacological agents and then irradiating the tumor with thermal or epithermal neutron beams [1].
• Two glioblastoma patients excluding other treatments, the only genuine Boron-neutron capture therapy cases, have been living for 39+ and 34+ months working full-scale without neurological deficit [2].
• Preclinical studies in animals show that several MAbs may bind to melanoma cells in sufficient quantities in vitro to localize the required amount of Boron per cell [3].
• However, no visual symptoms of B toxicity in plants were observed [4].
• The purpose of this study was to evaluate boron distribution for a safe and effective BNCT (Boron Neutron Capture Therapy) of liver metastases [5].

High impact information on boron

• Based on these findings and the response of animals and/or humans to low intakes of these elements, the following speculations have been presented: 1) Boron has a role that affects cell membrane characteristics and transmembrane signaling [6].
• Recently a cDNA clone encoding a H+/peptide cotransporter has been isolated from a rabbit intestinal cDNA library (Fei, Y.J., Kanai, Y., Nussberger, S., Ganapathy, V., Leibach, F.H., Romero, M.F., Singh, S.K., Boron, W. F., and Hediger, M. A. (1994) Nature 368, 563-566) [7].
• Microwave-Assisted, Boron Trichloride Mediated Acylation of Phenols-Synthesis of (o-Hydroxyaryl)(Aryl)methanones and Xanthones [8].
• Synthesis of Boron Cluster Lipids: closo-Dodecaborate as an Alternative Hydrophilic Function of Boronated Liposomes for Neutron Capture Therapy [9].
• Iron-reducing enrichments were obtained from leachate ponds at the U.S. Borax Company in Boron, Calif. Based on partial small-subunit (SSU) rRNA gene sequences (approximately 500 nucleotides), six isolates shared 98.9% nucleotide identity [10].

Biological context of boron

• RESULTS: Boron-containing, FR-targeted liposomes readily bound to KB cells, an FR-overexpressing cell line, and were internalized via FR-mediated endocytosis [11].
• High levels of soluble salts, indicated by the electrical conductivity (EC) of soil extracts, in tandem with an apparent phytotoxic effect from boron (B), apparently inhibited initial plant establishment as shown by substantially lower germination counts in treated soil [12].
• When the hyperaccumulator Thlaspi caerulescens was compared, the results were higher values of heavy metal and Boron accumulation, with a yield of 100 times more biomass [13].
• Strong positive correlations between SRP and B (also TP and B) across all the 54 river monitoring sites also confirm the primary importance of point source controls of phosphorus concentrations in these rivers, particularly during spring and summer low flows, which are times of greatest eutrophication risk [14].
• Kinetic Modeling of the Polymer-Derived Ceramics Route: Investigation of the Thermal Decomposition Kinetics of Poly[B-(methylamino)borazine] Precursors into Boron Nitride [15].

Anatomical context of boron

• 5. Boron concentrations in the breast, liver, thigh and bone tissue increased with increasing concentrations of supplemental boron [16].
• (3) Boron supplementation caused significant increases in splenic plasma cell count but decreased the proximal and distal tibia growth plate widths [17].
• Recently, we reported the cloning and expression of the rat renal electrogenic Na(+)-HCO(-)(3) cotransporter (rkNBC) in Xenopus oocytes [M. F. Romero, P. Fong, U. V. Berger, M. A. Hediger, and W. F. Boron. Am. J. Physiol. 274 (Renal Physiol. 43): F425-F432, 1998] [18].

Associations of boron with other chemical compounds

• Neodymium Iron Boron (NdFeB) rare earth permanent magnets have unique properties that enable them to fit easily onto the accessory mount of a clinical linear accelerator to partially sweep away electron contamination produced by the treatment head and block trays and thus increase skin sparing [19].
• We have synthesized a fluorescent probe for cathepsin D, where the pepstatin A was covalently conjugated with the BODIPY (Boron dipyrromethene difluoride) fluorophore [20].
• Double coaxial carbon nanotubes with nitrogen (N)-doped and boron (B)-doped multiwalls possess composite Raman characteristics, originating not only from the outer N-doped but also from inner B-doped layers [21].
• Effects of Surfactant and Boron Doping on the BWF Feature in the Raman Spectrum of Single-Wall Carbon Nanotube Aqueous Dispersions [22].
• A recent study on Xenopus oocytes [N. L. Nakhoul, M. F. Romero, B. A. Davis, and W. F. Boron. Am. J. Physiol. 274 (Cell Physiol. 43): C543-548, 1998] injected with carbonic anhydrase showed that expressing aquaporin 1 (AQP1) increases by approximately 40% the rate at which exposing the cell to CO2 causes intracellular pH to fall [23].

Analytical, diagnostic and therapeutic context of boron

• Analysis of Boron Distribution In Vivo for Boron Neutron Capture Therapy using Two Different Boron Compounds by Secondary Ion Mass Spectrometry [24].
• Such molecules may constitute powerful tools for applications like Boron Neutron Capture Therapy or Energy-Filtering Transmission Electron Microscopy [25].
• Boron neutron capture therapy (BNCT) is an experimental treatment modality which depends on a sufficient cellular uptake of Boron ((10)B) followed by an exposure to a thermal neutron beam from a nuclear reactor [26].
• Three ways of minimizing leakage are as follows: (1) Use a less leaky indicator, such as BCECF (Rink et al., 1982); (2) lower the incubation temperature; (3) continuously remove external indicator by perfusion technique (Boron, 1982) [27].
• The use of epithermal neutron beam in clinical trials of Boron Neutron Capture Therapy for patients with malignant brain tumors had been carried out for half a decade at the Brookhaven's Medical Reactor [28].

References