Semiconductors: Materials that have a limited and usually variable electrical conductivity. They are particularly useful for the production of solid-state electronic devices.Alpha Particles: Positively charged particles composed of two protons and two NEUTRONS, i.e. equivalent to HELIUM nuclei, which are emitted during disintegration of heavy ISOTOPES. Alpha rays have very strong ionizing power, but weak penetrability.Plastics: Polymeric materials (usually organic) of large molecular weight which can be shaped by flow. Plastic usually refers to the final product with fillers, plasticizers, pigments, and stabilizers included (versus the resin, the homogeneous polymeric starting material). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Actinium: Actinium. A trivalent radioactive element and the prototypical member of the actinide family. It has the atomic symbol Ac, atomic number 89, and atomic weight 227.0278. Its principal isotope is 227 and decays primarily by beta-emission.Astatine: Astatine. A radioactive halogen with the atomic symbol At, atomic number 85, and atomic weight 210. Its isotopes range in mass number from 200 to 219 and all have an extremely short half-life. Astatine may be of use in the treatment of hyperthyroidism.Lead Radioisotopes: Unstable isotopes of lead that decay or disintegrate emitting radiation. Pb atoms with atomic weights 194-203, 205, and 209-214 are radioactive lead isotopes.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Physics: The study of those aspects of energy and matter in terms of elementary principles and laws. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Polonium: Polonium. A radioactive element that is a member of the chalcogen family. It has the atomic symbol Po, atomic number 84, and the atomic weight of the isotope with the longest half-life (209Po) is 208.98. It decays by alpha-emission.Radiometry: The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.Radon: A naturally radioactive element with atomic symbol Rn, atomic number 86, and atomic weight 222. It is a member of the noble gas family found in soil, and is released during the decay of radium.Radium: Radium. A radioactive element of the alkaline earth series of metals. It has the atomic symbol Ra, atomic number 88, and atomic weight 226. Radium is the product of the disintegration of uranium and is present in pitchblende and all ores containing uranium. It is used clinically as a source of beta and gamma-rays in radiotherapy, particularly BRACHYTHERAPY.Nuclear Physics: The study of the characteristics, behavior, and internal structures of the atomic nucleus and its interactions with other nuclei. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Radioactivity: The spontaneous transformation of a nuclide into one or more different nuclides, accompanied by either the emission of particles from the nucleus, nuclear capture or ejection of orbital electrons, or fission. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Neutrons: Electrically neutral elementary particles found in all atomic nuclei except light hydrogen; the mass is equal to that of the proton and electron combined and they are unstable when isolated from the nucleus, undergoing beta decay. Slow, thermal, epithermal, and fast neutrons refer to the energy levels with which the neutrons are ejected from heavier nuclei during their decay.Neovascularization, Pathologic: A pathologic process consisting of the proliferation of blood vessels in abnormal tissues or in abnormal positions.Angiogenesis Inhibitors: Agents and endogenous substances that antagonize or inhibit the development of new blood vessels.Bismuth: A metallic element that has the atomic symbol Bi, atomic number 83 and atomic weight 208.98.Peptaibols: A group of peptides characterized by length of 1-2 dozen residues with a high proportion of them being non-proteinogenic, notably alpha-aminoisobutyric acid (Aib) and isovaline, and have a C-terminal amino alcohol and N terminal alkyl group. They are found in FUNGI and some are ANTI-INFECTIVE AGENTS. They form channels or pores in target organisms. The term is a contraction of peptide-Aib-alcohol.Bystander Effect: The result of a positive or negative response (to drugs, for example) in one cell being passed onto other cells via the GAP JUNCTIONS or the intracellular milieu.Radiobiology: Study of the scientific principles, mechanisms, and effects of the interaction of ionizing radiation with living matter. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Fibroblasts: Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.Radon Daughters: Short-lived radioactive decay products of radon that include 216-Po, 214-Pb, 214-Bi, and 214-Po. They have an effective half-life of about 30 minutes and are solids that can deposit on the bronchial airways during inhalation and exhalation. This results in exposure of the respiratory airways to alpha radiation and can lead to diseases of the respiratory system, including lung cancer. (From Casarett and Doull's Toxicology, 4th ed, p740)Xenon: A noble gas with the atomic symbol Xe, atomic number 54, and atomic weight 131.30. It is found in the earth's atmosphere and has been used as an anesthetic.Xenon Isotopes: Stable xenon atoms that have the same atomic number as the element xenon, but differ in atomic weight. Xe-124, 126, 128-131, 134, and 136 are stable xenon isotopes.Gamma Rays: Penetrating, high-energy electromagnetic radiation emitted from atomic nuclei during NUCLEAR DECAY. The range of wavelengths of emitted radiation is between 0.1 - 100 pm which overlaps the shorter, more energetic hard X-RAYS wavelengths. The distinction between gamma rays and X-rays is based on their radiation source.Visual Perception: The selecting and organizing of visual stimuli based on the individual's past experience.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Fluorine: A nonmetallic, diatomic gas that is a trace element and member of the halogen family. It is used in dentistry as flouride (FLUORIDES) to prevent dental caries.Americium: Americium. A completely man-made radioactive actinide with atomic symbol Am, atomic number 95, and atomic weight 243. Its valence can range from +3 to +6. Because of its nonmagnetic ground state, it is an excellent superconductor. It is also used in bone mineral analysis and as a radiation source for radiotherapy.Thorium Dioxide: Thorium oxide (ThO2). A radiographic contrast agent that was used in the early 1930s through about 1954. High rates of mortality have been linked to its use and it has been shown to cause liver cancer.Linear Energy Transfer: Rate of energy dissipation along the path of charged particles. In radiobiology and health physics, exposure is measured in kiloelectron volts per micrometer of tissue (keV/micrometer T).Centromere Protein B: A DNA-binding protein that interacts with a 17-base pair sequence known as the CENP-B box motif. The protein is localized constitutively to the CENTROMERE and plays an important role in its maintenance.Nucleosomes: The repeating structural units of chromatin, each consisting of approximately 200 base pairs of DNA wound around a protein core. This core is composed of the histones H2A, H2B, H3, and H4.DNA, Satellite: Highly repetitive DNA sequences found in HETEROCHROMATIN, mainly near centromeres. They are composed of simple sequences (very short) (see MINISATELLITE REPEATS) repeated in tandem many times to form large blocks of sequence. Additionally, following the accumulation of mutations, these blocks of repeats have been repeated in tandem themselves. The degree of repetition is on the order of 1000 to 10 million at each locus. Loci are few, usually one or two per chromosome. They were called satellites since in density gradients, they often sediment as distinct, satellite bands separate from the bulk of genomic DNA owing to a distinct BASE COMPOSITION.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Chromosomes, Artificial, Human: DNA constructs that are composed of, at least, all elements, such as a REPLICATION ORIGIN; TELOMERE; and CENTROMERE, required for successful replication, propagation to and maintainance in progeny human cells. In addition, they are constructed to carry other sequences for analysis or gene transfer.Centromere: The clear constricted portion of the chromosome at which the chromatids are joined and by which the chromosome is attached to the spindle during cell division.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Argon: Argon. A noble gas with the atomic symbol Ar, atomic number 18, and atomic weight 39.948. It is used in fluorescent tubes and wherever an inert atmosphere is desired and nitrogen cannot be used.Spectrometry, Mass, Electrospray Ionization: A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.Environment: The external elements and conditions which surround, influence, and affect the life and development of an organism or population.Electron Transport: The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)Indium: A metallic element, atomic number 49, atomic weight 114.82, symbol In. It is named from its blue line in the spectrum. (From Dorland, 28th ed)Blogging: Using an INTERNET based personal journal which may consist of reflections, comments, and often hyperlinks.Resins, Plant: Flammable, amorphous, vegetable products of secretion or disintegration, usually formed in special cavities of plants. They are generally insoluble in water and soluble in alcohol, carbon tetrachloride, ether, or volatile oils. They are fusible and have a conchoidal fracture. They are the oxidation or polymerization products of the terpenes, and are mixtures of aromatic acids and esters. Most are soft and sticky, but harden after exposure to cold. (From Grant & Hackh's Chemical Dictionary, 5th ed & Dorland, 28th ed)Electronics: The study, control, and application of the conduction of ELECTRICITY through gases or vacuum, or through semiconducting or conducting materials. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Copyright: It is a form of protection provided by law. In the United States this protection is granted to authors of original works of authorship, including literary, dramatic, musical, artistic, and certain other intellectual works. This protection is available to both published and unpublished works. (from Circular of the United States Copyright Office, 6/30/2008)Blastocladiella: A genus of aquatic fungi of the family Blastocladiaceae, order Blastocladiales, used in the study of zoospore formation.Chitin Synthase: An enzyme that converts UDP glucosamine into chitin and UDP. EC 2.4.1.16.Cowpox virus: A species of ORTHOPOXVIRUS that is the etiologic agent of COWPOX. It is closely related to but antigenically different from VACCINIA VIRUS.WalesEngland

Loss of normal G1 checkpoint control is an early step in carcinogenesis, independent of p53 status. (1/190)

Recent studies have described a diminished radiation-induced G1 arrest in some wild-type (wt) p53 human tumor cell lines compared to normal human fibroblasts. However, the significance of this finding was unclear, particularly because tumor cell lines may have accumulated additional genetic changes after long periods in culture. Because malignant transformation of individual cells is thought to be an early step in carcinogenesis, we have used a model system of normal and transformed mouse fibroblast 10T1/2 cell clones to examine whether loss of G1 checkpoint control may be an early event in tumor development and to study the relationships between G1 arrest, radiosensitivity, and genetic alterations. Twelve transformed clones were established from type III foci induced by irradiation of normal 10T1/2 cells and were compared with six clones derived from wt 10T1/2 cells. Three of the transformed clones expressed mutant p53; two of these had the same point mutation at codon 132 (exon 5), and one had a point mutation at codon 135. The remaining transformed and normal clones had wt p53 status. The radiosensitivity of transformed clones, as measured by a clonogenic assay, was similar to that of normal clones; the three clones with mutant p53 did not differ from the others. There was no relationship between G1 arrest and radiosensitivity. Normal 10T1/2 cell clones showed a transient G1 arrest lasting approximately 9 h after 6 Gy of irradiation. This G1 arrest was either absent or markedly reduced in all of the transformed clones, regardless of p53 status. These results suggest that diminished G1 checkpoint control is an early event in the process of carcinogenesis that is associated with the malignant transformation of individual cells and is independent of p53 status.  (+info)

Targeted cytoplasmic irradiation with alpha particles induces mutations in mammalian cells. (2/190)

Ever since x-rays were shown to induce mutation in Drosophila more than 70 years ago, prevailing dogma considered the genotoxic effects of ionizing radiation, such as mutations and carcinogenesis, as being due mostly to direct damage to the nucleus. Although there was indication that alpha particle traversal through cellular cytoplasm was innocuous, the full impact remained unknown. The availability of the microbeam at the Radiological Research Accelerator Facility of Columbia University made it possible to target and irradiate the cytoplasm of individual cells in a highly localized spatial region. By using dual fluorochrome dyes (Hoechst and Nile Red) to locate nucleus and cellular cytoplasm, respectively, thereby avoiding inadvertent traversal of nuclei, we show here that cytoplasmic irradiation is mutagenic at the CD59 (S1) locus of human-hamster hybrid (AL) cells, while inflicting minimal cytotoxicity. The principal class of mutations induced are similar to those of spontaneous origin and are entirely different from those of nuclear irradiation. Furthermore, experiments with radical scavenger and inhibitor of intracellular glutathione indicated that the mutagenicity of cytoplasmic irradiation depends on generation of reactive oxygen species. These findings suggest that cytoplasm is an important target for genotoxic effects of ionizing radiation, particularly radon, the second leading cause of lung cancer in the United States. In addition, cytoplasmic traversal by alpha particles may be more dangerous than nuclear traversal, because the mutagenicity is accomplished by little or no killing of the target cells.  (+info)

Preparation of alpha-emitting 213Bi-labeled antibody constructs for clinical use. (3/190)

Preclinical evaluation of alpha particle-emitting 213Bi-labeled antibody constructs have demonstrated the specificity and potency of these agents in a variety of cancer systems. The transition of a 213Bi-radiolabeled antibody from a preclinical construct to a clinical drug represented a difficult task that involved development of reliable and validated methods to provide multiple MBq quantities of a pure, immunoreactive agent that met pharmaceutical standards to treat patients. METHODS: The methods used for the preparation of (213Bi)CHX-A-diethylenetriamine pentaacetic acid (DTPA)-HuM195, an alpha particle-emitting anti-CD33 antibody construct for therapy of myeloid leukemias, is used as a specific example. This article describes methods for reagent purification, drug labeling, radioprotection and chromatographic purification. Quality of the drug is evaluated using radiochemical incorporation and purity assays with instant thin-layer chromatography (ITLC) and high-performance liquid chromatography (HPLC), determination of cell-based antibody total immunereactivity, small animal safety, pyrogen level, sterility and radionuclidic purity. RESULTS: Sixty-seven doses were prepared. Individual doses ranged from 148 to 814 MBq. Specific activities ranged from 329 to 766 MBq/mg. The radiolabeling efficiency (median +/- SD) of CHX-A-DTPA-HuM195 with 213Bi was 81% +/- 9% (n = 67) after 9 min. The construct was purified by size-exclusion chromatography and was found to be 99% +/- 2% pure (n = 67) by either ITLC or HPLC methods. The immunoreactivity of (213Bi)CHX-A-DTPA-HuM195 was 89% +/- 9% (n = 44) and was independent of the specific activity. The formulated pharmaceutical was found to contain < or =4 +/- 1 EU/mL pyrogens (n = 66); all samples examined were sterile. An 225Ac radionuclidic impurity was present at a level of 0.04 +/- 0.03 x 10(-6)/mL (n = 10) in a product volume of 7.4 +/- 0.5 mL (n = 67). Each of the 67 doses was injected intravenously into patients without complication as part of a phase I clinical trial. CONCLUSION: These data show that 213Bi-labeled antibody constructs can be prepared and administered safely to humans at a wide range of therapeutic levels.  (+info)

Pharmacokinetics and dosimetry of an alpha-particle emitter labeled antibody: 213Bi-HuM195 (anti-CD33) in patients with leukemia. (4/190)

Data from nine patients with leukemia participating in a phase I activity-escalation study of HuM195, labeled with the alpha-particle emitter 213Bi (half-life = 45.6 min), were used to estimate pharmacokinetics and dosimetry. This is the first trial using an alpha-particle emitter in humans. The linear energy transfer of alpha particles is several hundredfold greater than that of beta emissions. The range in tissue is approximately 60-90 microm. METHODS: The activity administered to patients ranged from 0.6 to 1.6 GBq. Patient imaging was initiated at the start of each injection. Thirty 1-min images followed by ten 3-min images were collected in dynamic mode; a 20% photopeak window centered at 440 keV was used. Blood samples were collected until 3 h postinjection and counted in a gamma counter. Contours around the liver and spleen were drawn on the anterior and posterior views and around a portion of the spine on the posterior views. No other organs were visualized. RESULTS: The percentage injected dose in the liver and spleen volumes increased rapidly over the first 10-15 min to a constant value for the remaining hour of imaging, yielding a very rapid uptake followed by a plateau in the antibody uptake curves. The kinetic curves were integrated to yield cumulated activity. The mean energy emitted per nuclear transition for 213Bi and its daughters, adjusted by a relative biologic effectiveness of 5 for alpha emissions, was multiplied by the cumulated activity to yield the absorbed dose equivalent. Photon dose to the total body was determined by calculating a photon-absorbed fraction. The absorbed dose equivalent to liver and spleen volumes ranged from 2.4 to 11.2 and 2.9 to 21.9 Sv, respectively. Marrow (or leukemia) mean dose ranged from 6.6 to 12.2 Sv. The total-body dose (photons only) ranged from 2.2 x 10(-4) to 5.8 x 10(-4) Gy. CONCLUSION: This study shows that patient imaging of 213Bi, an alpha-particle emitter, labeled to HuM195 is possible and may be used to derive pharmacokinetics and dosimetry. The absorbed dose ratio between marrow, liver and spleen volumes and the whole body for 213Bi-HuM195 is 1000-fold greater than that commonly observed with beta-emitting radionuclides used for radioimmunotherapy.  (+info)

Localization of tumor suppressor gene candidates by cytogenetic and short tandem repeat analyses in tumorigenic human bronchial epithelial cells. (5/190)

Radon exposure is associated with increased risk for bronchogenic carcinoma. Mutagenesis analyses have revealed that radon induces mostly multi-locus chromosome deletions. Based on these findings, it was hypothesized that deletion analysis of multiple radon-induced malignant transformants would reveal common mutations in chromosomal regions containing tumor suppressor genes responsible for malignant transformation. This hypothesis was supported by a previous study in which tumorigenic derivatives of the human papillomavirus 18-immortalized human bronchial epithelial cell line BEP2D were established following irradiation with 30 cGy of high linear energy transfer radon-simulated alpha-particles. Herein, we describe the analyses of 10 additional tumorigenic derivative cell lines resulting from the irradiation of five additional independent BEP2D populations. The new transformants have common cytogenetic changes, including the loss of chromosome (ch)Y, one of three copies of ch8, one of two copies of ch11p15-pter and one of three copies of ch14. These changes are the same as those reported previously. Analysis of PCR-amplified short tandem repeats of informative loci confirmed the loss of heterozygosity (LOH) at 12 loci spanning the length of ch8 in cell lines from four of the total of eight irradiation treatments to date and the loss of chY in all cell lines (8 of 8). LOH analysis with a total of 17 informative loci confirmed loss on ch14 in transformants from seven of eight irradiation treatments and indicated a 0.5-1.7 cM region of common involvement centered around locus D14S306. No LOH was detected at any of the informative loci on ch11. The overall results support our stated hypothesis. Further studies are currently in progress to determine whether the ch8 and ch14 regions contain genes with tumor suppressor function in bronchial epithelial cells.  (+info)

Induction of a bystander mutagenic effect of alpha particles in mammalian cells. (6/190)

Ever since the discovery of X-rays was made by Rontgen more than a hundred years ago, it has always been accepted that the deleterious effects of ionizing radiation such as mutation and carcinogenesis are attributable mainly to direct damage to DNA. Although evidence based on microdosimetric estimation in support of a bystander effect appears to be consistent, direct proof of such extranuclear/extracellular effects are limited. Using a precision charged particle microbeam, we show here that irradiation of 20% of randomly selected A(L) cells with 20 alpha particles each results in a mutant fraction that is 3-fold higher than expected, assuming no bystander modulation effect. Furthermore, analysis by multiplex PCR shows that the types of mutants induced are significantly different from those of spontaneous origin. Pretreatment of cells with the radical scavenger DMSO had no effect on the mutagenic incidence. In contrast, cells pretreated with a 40 microM dose of lindane, which inhibits cell-cell communication, significantly decreased the mutant yield. The doses of DMSO and lindane used in these experiments are nontoxic and nonmutagenic. We further examined the mutagenic yield when 5-10% of randomly selected cells were irradiated with 20 alpha particles each. Results showed, likewise, a higher mutant yield than expected assuming no bystander effects. Our studies provide clear evidence that irradiated cells can induce a bystander mutagenic response in neighboring cells not directly traversed by alpha particles and that cell-cell communication process play a critical role in mediating the bystander phenomenon.  (+info)

Factors underlying the cell growth-related bystander responses to alpha particles. (7/190)

Increases in cell proliferation are widely viewed as being of importance in carcinogenesis. We report that exposure of normal human lung fibroblasts to a low dose of alpha particles like those emitted by radon/radon progeny stimulates their proliferation in vitro, and this response also occurs when unirradiated cells are treated with supernatants from alpha-irradiated cells. We attribute the promitogenic response to superoxide dismutase- and catalase-inhibitable a particle-induced increases in the concentrations of transforming growth factor beta1 (TGF-beta1) in cell supernatants. TGF-beta1 at concentrations commensurate with those in the supernatants capably induces increases in intracellular reactive oxygen species (ROS) in unirradiated cells. Furthermore, the addition of supernatants from alpha-irradiated cells to unirradiated cells decreases cellular levels of TP53 and CDKN1A and increases CDC2 and proliferating cell nuclear antigen in the latter. Like the increased intracellular ROS bystander effect, this "decreased TP53/CDKN1A response" can be mimicked in otherwise untreated cells by the addition of low concentrations of TGF-beta1. Our results indicate that alpha particle-associated increases in cell growth correlate with intracellular increases in ROS along with decreases in TP53 and CDKN1A, and that these cellular responses are mechanistically coupled. As well, the proliferating cell nuclear antigen and CDC2 increases that occur along with the decreased TP53/CDKN1A bystander effect also would expectedly favor enhanced cell growth. Such processes may account for cell hyperplastic responses in the conducting airways of the lower respiratory track that occur after inhalation exposure to radon/ radon progeny, as well as, perhaps, other ROS-associated environmental stresses.  (+info)

Establishment of a radiation- and estrogen-induced breast cancer model. (8/190)

It is well accepted that cancer arises in a multistep fashion in which exposure to environmental carcinogens is a major etiological factor. The aim of this work was to establish an experimental breast cancer model in order to understand the mechanism of neoplastic transformation induced by high LET radiation in the presence of 17beta-estradiol (E). Immortalized human breast cells (MCF-10F) were exposed to low doses of high LET alpha particles (150 keV/microm) and subsequently cultured in the presence or absence of E for periods of up to 10 months post-irradiation. MCF-10F cells irradiated with either a single 60 cGy dose or 60/60 cGy doses of alpha particles showed gradual phenotypic changes including altered morphology, increase in cell proliferation relative to the control, anchorage-independent growth and invasive capability before becoming tumorigenic in nude mice. In alpha particle-irradiated cells and in those cells subsequently cultured in the presence of E, increased BRCA1, BRCA2 and RAD51 expression were detected by immunofluorescence staining and quantified by confocal microscopy. These studies showed that high LET radiation such as that emitted by radon progeny, in the presence of estrogen, induced a cascade of events indicative of cell transformation and tumorigenicity in human breast epithelial cells.  (+info)

  • According to Encyclopædia Britannica, a beta particle can have either a negative charge (if it is an electron) or a positive charge (a positron). (reference.com)
  • Suppose the colliding particle has more than sufficient energy to affect the removal of one electron, what is the net result of the collision? (caltech.edu)
  • These data are required to estimate the absorbed dose on a cellular level as alpha particles have a limited range and traverse only a few cells.Results show that alpha particle, photon, electron, and muon tracks were detected and resolved by Timepix detector.The current study demonstrated that individual alpha particle emissions, resulting from targeted alpha therapy, can be visualised and quantified using Timepix detector. (nih.gov)
  • Results show that alpha particle, photon, electron, and muon tracks were detected and resolved by Timepix detector. (nih.gov)
  • We investigated the feasibility of imaging alpha particle emissions in tumour sections from mice treated with Thorium-227 (using APOMAB), with and without prior chemotherapy and Timepix detector. (nih.gov)
  • Measured alpha particle hits per unit tumour area per 1 hour for two groups of tumour sections: 4 sections with and 3 sections without application of chemotherapy prior to administration of Th-227 radioimmunoconjugate. (nih.gov)
  • In addition it was shown that at least one of the two resonances which are in the neighborhood of 900 kev must yield short range alpha-particles whose angular distribution is not spherically symmetric. (caltech.edu)
  • In addition, the slowly growing TK mutants that constitute the majority of X-ray-induced TK mutants of TK6 were recovered in lower proportions following α-particle exposures. (elsevier.com)
  • These data are required to estimate the absorbed dose on a cellular level as alpha particles have a limited range and traverse only a few cells. (nih.gov)
  • If substances emitting alpha particles are ingested, inhaled, injected or introduced through the skin, then it could result in a measurable dose through their ionising effect which eventually changes the polarity of parts of the cells in your body. (enotes.com)
  • In an effort to better understand these properties, we have examined the effects of α-particles on these cells. (elsevier.com)
  • How then can alpha particles cause human biological damage? (enotes.com)
  • Actinium-225 ((225)Ac)-E4G10, an alpha-emitting antibody construct reactive with the unengaged form of vascular endothelial cadherin, is capable of potent, selective killing of tumor neovascular endothelium and late endothelial progenitors in bone-marrow and blood. (nih.gov)
  • For my project I have to monitor the efficiency of zinc sulphide detectors for monitoring alpha particles in liquid solutions. (physicsforums.com)
  • Quantitative imaging of 223Ra-chloride (Alpharadin) for targeted alpha-emitting radionuclide therapy of bone metastases. (lu.se)