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Gabriel, C., Gabriel, S., & Corthout, E. (1996). The dielectric properties of biological tissues: I. Literature survey. Phys Med Biol, 41(11), 2231–2249.
Abstract: The dielectric properties of tissues have been extracted from the literature of the past five decades and presented in a graphical format. The purpose is to assess the current state of knowledge, expose the gaps there are and provide a basis for the evaluation and analysis of corresponding data from an on-going measurement programme.
Keywords: Adipose Tissue/physiology; Animals; Blood Physiological Phenomena; Bone and Bones/*physiology; Brain/physiology; *Electric Conductivity; *Electrophysiology; Heart/physiology; Humans; Kidney/physiology; Liver/physiology; Lung/physiology; Muscles/physiology; Organ Specificity; Skin Physiological Phenomena; Spleen/physiology
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Raylman, R. R., Clavo, A. C., & Wahl, R. L. (1996). Exposure to strong static magnetic field slows the growth of human cancer cells in vitro. Bioelectromagnetics, 17(5), 358–363.
Abstract: Proposals to enhance the amount of radiation dose delivered to small tumors with radioimmunotherapy by constraining emitted electrons with very strong homogeneous static magnetic fields has renewed interest in the cellular effects of prolonged exposures to such fields. Past investigations have not studied the effects on tumor cell growth of lengthy exposures to very high magnetic fields. Three malignant human cell lines, HTB 63 (melanoma), HTB 77 IP3 (ovarian carcinoma), and CCL 86 (lymphoma: Raji cells), were exposed to a 7 Tesla uniform static magnetic field for 64 hours. Following exposure, the number of viable cells in each group was determined. In addition, multicycle flow cytometry was performed on all cell lines, and pulsed-field electrophoresis was performed solely on Raji cells to investigate changes in cell cycle patterns and the possibility of DNA fragmentation induced by the magnetic field. A 64 h exposure to the magnetic field produced a reduction in viable cell number in each of the three cell lines. Reductions of 19.04 +/- 7.32%, 22.06 +/- 6.19%, and 40.68 +/- 8.31% were measured for the melanoma, ovarian carcinoma, and lymphoma cell lines, respectively, vs. control groups not exposed to the magnetic field. Multicycle flow cytometry revealed that the cell cycle was largely unaltered. Pulsed-field electrophoresis analysis revealed no increase in DNA breaks related to magnetic field exposure. In conclusion, prolonged exposure to a very strong magnetic field appeared to inhibit the growth of three human tumor cell lines in vitro. The mechanism underlying this effect has not, as yet, been identified, although alteration of cell growth cycle and gross fragmentation of DNA have been excluded as possible contributory factors. Future investigations of this phenomenon may have a significant impact on the future understanding and treatment of cancer.
Keywords: Carcinoma/*pathology/therapy; Cell Cycle; Cell Division; Cell Survival; DNA Fragmentation; Electrophoresis, Gel, Pulsed-Field; Female; Flow Cytometry; G1 Phase; Humans; Lymphoma/*pathology/therapy; *Magnetics/therapeutic use; Melanoma/*pathology/therapy; Ovarian Neoplasms/*pathology/therapy; S Phase; Tumor Cells, Cultured
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Kavet, R. (1996). EMF and current cancer concepts. Bioelectromagnetics, 17(5), 339–357.
Abstract: Exposure to power frequency electric and magnetic fields (EMF) is ubiquitous, and a body of epidemiologic studies has produced evidence suggestive of a possible link between EMF exposure and cancer of several types. This paper provides a perspective that holds key findings in the EMF literature against the background of important models and established principles in cancer biology. It is intended primarily for scientists whose expertise lies outside of cancer biology and animal bioassays. Current thinking holds that carcinogenesis is a multistep process that requires at least two genotoxic events in its critical path but that is facilitated by nongenotoxic proliferative effects on target cells. EMF, which itself is not believed to be genotoxic, could influence carcinogenesis if it exerted either direct or indirect effects on target cell turnover. Such effects could operate through receptor-mediated or nonreceptor-mediated pathways. However, effects relevant to carcinogenesis have not been confirmed, and a mode of action for EMF has not been determined. Chronic bioassays in rodents are in progress to examine the potential carcinogenicity of EMFs. EMF research has the opportunity to capitalize on the recent major advances in our understanding of carcinogenic processes.
Keywords: Animals; Biological Assay; Biology; Cell Division/physiology; Cocarcinogenesis; Disease Models, Animal; Electricity/adverse effects; Electromagnetic Fields/*adverse effects; Environmental Exposure; Epidemiologic Methods; Humans; Magnetics/adverse effects; Neoplasms/*etiology/genetics; Neoplasms, Experimental/etiology/genetics; Receptors, Cell Surface/physiology; Rodentia
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Doida, Y., Miller, M. W., Brayman, A. A., & Carstensen, E. L. (1996). A test of the hypothesis that ELF magnetic fields affect calcium uptake in rat thymocytes in vitro. Biochem Biophys Res Commun, 227(3), 834–838.
Abstract: The experiment's objective was to test the statistical hypothesis that a 60-min exposure of rat thymocytes in vitro to a unique combination of static and a.c. magnetic fields results in suppression of calcium influx triggered by concanavalin A (Con A). Con A (10 micrograms/ml) induced about a 50% increase in 45Ca2+ uptake relative to no Con A (control). Magnetic field exposures had no statistically significant effect on Con A-stimulated calcium uptake. The data did not support the hypothesis.
Keywords: Animals; Calcium/*metabolism; Concanavalin A; Ion Transport; *Magnetics; Male; Mitogens/pharmacology; Rats; Rats, Sprague-Dawley; Thymus Gland/cytology/drug effects/*metabolism
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De Luca, F., Cametti, C., Zimatore, G., Maraviglia, B., & Pachi, A. (1996). Use of low-frequency electrical impedance measurements to determine phospholipid content in amniotic fluid. Phys Med Biol, 41(9), 1863–1869.
Abstract: In this report we propose a new method for an in vitro test of the foetal lung maturity based on the measurement of the electrical conductivity of the overall amniotic fluid obtained from transabdominal amniocentesis, since this quantity can be linked to a first approximation in a very simple way to the phospholipid content. We have carried out measurements of 85 different samples of amniotic fluid as a function of gestation weeks and we have observed a pronounced change of the electrical conductivity that reflects the increase in the phospholipid concentration occurring at the end of normal pregnancies. The method could be further developed to obtain similar information on in vivo experiments by means of bioelectric impedance tomography, taking advantage of the frequency dependence of the tissue electrical impedance.
Keywords: *Amniocentesis; Amniotic Fluid/*chemistry/*physiology; Electric Conductivity; Electric Impedance; Female; Gestational Age; Humans; Phospholipids/*analysis; Pregnancy; Pregnancy Trimester, Second; Pregnancy Trimester, Third
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