Effects of magnetic fields on the accumulation of thiobarbituric acid reactive substances induced by iron salt and H(2)O(2) in mouse brain homogenates or phosphotidylcholine.

In this study, we examined the effects of magnetic fields (MFs) on the generation of thiobarbituric acid reactive substances (TBARS) in the mouse brain homogenates or phosphotidylcholine (PC) solution, incubated with FeCl(3) and/or H(2)O(2). Active oxygen species were generated and lipid peroxidation was induced in mouse brain homogenates by incubation with iron ions, resulting in the accumulation of TBARS. Lipid peroxidation was induced in PC by incubation with iron ions and H(2)O(2).

Magnetic fields and lipoic acid influence the respiratory burst in activated rat peritoneal neutrophils.

When rat (Sprague-Dawley, male) peritoneal neutrophils are exposed to 60 Hz, 1 Gauss, magnetic fields and activated by phorbor 12-myristate 13-acetate they undergo an enhanced respiratory burst (S. Roy, Y. Noda, V.

Pulsed magnetic fields enhance nitric oxide synthase activity in rat cerebellum.

The effect of pulsed magnetic fields on nitric oxide synthase (NOS) activity in the rat brain was investigated. Sprague-Dawley rats (male, 200-250 g body weight) brain were dissected regionally, and the crude enzyme solutions were treated with pulsed DC, AC or static DC magnetic fields at 0 degrees C for 1 h. After exposure, NOS activity was measured as nitrite and nitrate levels generated from incubation with arginine, CaCl(2) and beta-nicotinamide adenine dinucleotide phosphate.

Environmental magnetic fields inhibit the antiproliferative action of tamoxifen and melatonin in a human breast cancer cell line.

We have previously reported that environmental-level magnetic fields (1.2 microT [12 milligauss], 60 Hz) block the growth inhibition of the hormone melatonin (10(-9) M) on MCF-7 human breast cancer cells in vitro. We now report that the same 1.

Experimental evidence for 60 Hz magnetic fields operating through the signal transduction cascade. Effects on calcium influx and c-MYC mRNA induction.

We tested the hypothesis that early alterations in calcium influx induced by an imposed 60 Hz magnetic field are propagated down the signal transduction (ST) cascade to alter c-MYC mRNa induction. To test this we measured both ST parameters in the same cells following 60 Hz magnetic field exposures in a specialized annular ring device (220 G (22 mT), 1.7 mV/cm maximal E(induced), 37 degrees C, 60 min).

ELF magnetic fields, breast cancer, and melatonin: 60 Hz fields block melatonin's oncostatic action on ER+ breast cancer cell proliferation.

In this study we investigated whether a 60 Hz magnetic field can act at the cellular level to influence the growth of human estrogen-dependent breast cancer cells. Our experimental design assessed cell proliferation of a human breast cancer cell line, MCF-7, in the absence or the presence of melatonin which inhibits growth at a physiological concentration of 10(-9) M. In three experiments, continuous exposure to average sinusoidal 60 Hz magnetic fields of 1.

Calcium signaling in lymphocytes and ELF fields. Evidence for an electric field metric and a site of interaction involving the calcium ion channel.

Calcium influx increased during mitogen-activated signal transduction in thymic lymphocytes exposed to a 22 mT, 60 Hz magnetic field (E induced = 1.7 mV/cm, 37 degrees C, 60 min). To distinguish between an electric or a magnetic field dependence a special multi-ring annular cell culture plate based on Faraday's Law of Induction was employed.

Time-varying and static magnetic fields act in combination to alter calcium signal transduction in the lymphocyte.

We have tested the hypothesis that extremely low frequency (ELF) time-varying magnetic fields act in combination with static magnetic fields to alter calcium signalling in the lymphocyte. Results indicate that a 60-min exposure of thymic lymphocytes at 37 +/- 0.05 degrees C to a 16 Hz, 421 mG (42.

Nonthermal 60 Hz sinusoidal magnetic-field exposure enhances 45Ca2+ uptake in rat thymocytes: dependence on mitogen activation.

The effect of a 60 Hz sinusoidal magnetic field of nonthermal intensity on Ca2+ metabolism in rat thymic lymphocytes (thymocytes) was assessed in resting cells and in cells activated with the mitogen Concanavalin A (Con A). A 60 min exposure at 37 degrees C to an induced electric field of 1.0 mV/cm produced an average 2.

Quantitative HPLC analysis of human plaque proteins in coronary and thoracic aorta arteries.

Quantitative HPLC analysis of saline-soluble proteins obtained from human coronary and thoracic aorta plaque and from whole internal mammary artery were performed. Protein extracts were characterized by anion exchange and reverse-phase HPLC and the integrated chromatographs revealed significant differences in both peak retention times and areas for protein species from coronary artery compared to thoracic aorta artery plaque. Coronary artery plaque proteins possessed a high degree of cationic charge and polarity compared to those present in thoracic aorta plaque and normal mammary artery.

Microwaves and the cell membrane. IV. Protein shedding in the human erythrocyte: quantitative analysis by high-performance liquid chromatography.

The erythrocyte responds to microwave fields by shedding at least 11 low-molecular-weight proteins of less than or equal to 31,000 Da, with components of 28,000-31,000 Da released during the destabilization of divalent calcium-protein bridges [R.P. Liburdy and P.

Microwaves and the cell membrane. III. Protein shedding is oxygen and temperature dependent: evidence for cation bridge involvement.

Microwaves (2450 MHz, 60 mW/g) are shown to result in the release or shedding of at least 11 low-molecular-weight proteins (less than or equal to 31,000 Da) from rabbit erythrocytes maintained in physiological buffer. Protein release was detected by gel electrophoresis of cell-free supernatants using sensitive silver staining. This release is oxygen dependent and occurs in 30 min for exposures conducted within the special temperature region of 17-21 degrees C, which is linked to a structural or conformational transition in the cell membrane.

Magnetic field-induced drug permeability in liposome vesicles.

Liposome vesicles maintained in a uniform static magnetic field release a chemotherapeutic drug (ARA-C, MW = 243) at temperatures approaching the phase-transition region where these liposomes are not normally leaky. Drug release is rapid, and a maximum difference between treated and unexposed liposomes of 30% of the total maximal release of ARA-C was observed within 1 min in a magnetic field. Dose-effect studies conducted between 0.

Microwave-stimulated drug release from liposomes.

Microwaves (2450 MHz) are shown to stimulate the release of an aqueous chemotherapeutic drug from phospholipid vesicles. This effect occurs at temperatures below the membrane phase transition temperature of 41 degrees C where these liposomes are normally not leaky. In buffered saline, microwave exposure (60 mW/g) triggers the onset of drug release at 33 degrees C, whereas in plasma a near maximal release is observed as low as 27 degrees C.

Microwaves and the cell membrane. II. Temperature, plasma, and oxygen mediate microwave-induced membrane permeability in the erythrocyte.

Microwaves (2450 MHz) are shown to increase 22Na permeability of rabbit erythrocytes for exposures only within the narrow temperature range of 17.7 to 19.5 degrees C (Tc) which coincides with a nonlinearity in the Arrhenius plot reflecting an apparent membrane phase transition.

Radiofrequency radiation and the immune system. Part 3. In vitro effects on human immunoglobin and on murine T- and B-lymphocytes.

Radiofrequency radiation (RFR) altered the physical separation of immunoglobulin (Ig) and of T- and B-lymphocytes during liquid gel chromatography. Exposure of human serum to a 10 MHz electric field (8500 V/m, less than or equal to 0.134 W kg-1) during chromatography resulted in accelerated elution of the IgM, IgA and IgG fractions.

Microwave bioeffects in the erythrocyte are temperature and pO2 dependent: cation permeability and protein shedding occur at the membrane phase transition.

Microwave exposure (2450 MHz, 60 mW/g, CW) of rabbit erythrocytes increases Na passive transport only at membrane phase transition temperatures (Tc) of 17-19 degrees C. This permeability effect is enhanced for relative hypoxia which is characteristic of intracellular oxygen tension (pO2 less than or equal to 5 mm Hg). Neither the permeability nor the pO2 effects are observed in temperature-matched (+/- 0.

Indium-114m in dual-nuclide studies with Cr-51: comparison with indium-111.

Simultaneously radioassay of In-111 and In-114m, each in the presence of Cr-51, has been investigated. Presented here are data demonstrating the efficacy of using In-114m in a dual radioassay with Cr-51, a radiolabel currently used in many cellular research applications. In-111 (T1/2, 2.