Immune System

Impact of extremely low frequency electromagnetic fields on CD4 expression in peripheral blood mononuclear cells

Unknown authors · 1999

Cytoplasmic Ca2+ oscillations in human leukemia T-cells are reduced by 50 Hz magnetic fields

Unknown authors · 1999

Researchers investigated the effect of 50 Hz magnetic fields on the cytosolic calcium oscillator in Jurkat E6.1 cells at field strengths from 0 to 0.40 mT root mean square. The total spectral power of the cytosolic Ca2+ oscillator was reduced by magnetic field exposure and the effect increased in a dose-response manner. This reduction was also observed in the 0-10 mHz subinterval of the oscillation spectrum, while higher frequency subintervals showed no significant change.

Occupational exposure to high frequency electromagnetic fields and its effect on human immune parameters.

Tuschl et al. · 1999

Different kinds of field probes were used to measure electric and magnetic field strength and the whole body exposure of medical personnel operating shortwave, decimeter wave and microwave units was calculated. The study recorded a considerable excess of recommended exposure limits in the vicinity of shortwave diathermy devices used for medical treatment of patients. Eighteen exposed and thirteen control persons, matched by sex and age, were examined, and total leucocyte and lymphocyte counts were performed and leucocytic subpopulations determined by flow cytometry and monoclonal antibodies against surface antigens. Lymphocytes were stimulated by mitogen phytohemagglutinin and their proliferation measured by a flow cytometric method.

In vivo exposure of rats to GSM-modulated microwaves: flow cytometry analysis of lymphocyte subpopulations and of mitogen stimulation.

Chagnaud JL, Veyret B · 1999

Researchers investigated the effects of GSM-modulated microwaves on lymphocyte sub-populations and mitogenic responses in Sprague-Dawley rats. No alterations were found in the surface phenotype of splenic lymphocytes or in their mitogenic activity.

The effect of various occupational exposures to microwave radiation on the concentrations of immunoglobulins and T lymphocyte subsets

Moszczynski P et al. · 1999

Researchers assessed immunoglobulin concentrations and T lymphocyte subsets in workers occupationally exposed to microwave radiation. Workers at a TV retransmission center and satellite communications center showed increased IgG and IgA concentrations and decreased lymphocyte and T8 cell counts. Radar operators showed elevated IgM concentration and decreased total T8 cell count.

Animal study on electromagnetic field biological potency.

Trosic I, Matausicpisl M, Radalj Z, Prlic I, · 1999

The remaining 20 rats served as control. Exposed rats showed a decreasing tendency in total leukocyte and relative lymphocyte counts and a slight increase in granulocyte and erythrocyte counts.

Microwaves and cellular immunity: II. Immunostimulating effects of microwaves and naturally occurring antioxidant nutrients

E.G Novoselova, E.E Fesenko, V.R Makar, V.B Sadovnikov · 1999

Researchers tested the effect of 8.15–18 GHz microwave radiation at a power density of 1 μW/cm2 on TNF production and immune response. A single 5-hour whole-body exposure induced a significant increase in TNF production in peritoneal macrophages and splenic T cells, and the mitogenic response in T lymphocytes also increased. The activation of cellular immunity was observed within 3 days after exposure. A diet containing β-carotene, α-tocopherol, and ubiquinone Q9 increased the activity of macrophages and T cells from irradiated mice.

[Stimulation of murine natural killer cells by weak electromagnetic waves in the centimeter range].

Fesenko EE et al. · 1999

Researchers investigated how weak electromagnetic waves in the centimeter range affected the cytotoxic activity of natural killer cells in mice. Irradiation at 8.15 to 18 GHz at 1 microwatt per square centimeter increased the cytotoxic activity of natural killer cells of rat spleen. In mice exposed for 24 to 72 hours, natural killer cell activity increased by 130 to 150%, and this elevated activity persisted for 24 hours after exposure ended. Microwave irradiation of animals in vivo for 3.5 and 5 hours, and a short exposure of splenic cells in vitro, did not affect natural killer cell activity.

Microwaves and cellular immunity. I. Effect of whole body microwave irradiation on tumor necrosis factor production in mouse cells.

Fesenko, EE, Makar, VR, Novoselova, EG, Sadovnikov, VB, · 1999

Researchers exposed male NMRI mice to whole body microwave irradiation at 8.15-18 GHz and a power density of 1 microW/cm2 and measured tumor necrosis factor (TNF) production in immune cells. Shorter exposures ranging from 5 hours to 3 days significantly enhanced TNF production in peritoneal macrophages and splenic T lymphocytes. Chronic irradiation for 7 days decreased TNF production in peritoneal macrophages. Microwave treatment increased endogenously produced TNF more effectively than lipopolysaccharide, described as one of the most potent stimuli of this cytokine.

Effects of 60 Hz magnetic field exposure on polymorphonuclear leukocyte activation.

Khadir R, Morgan JL, Murray JJ. · 1999

Researchers investigated the effects of a sinusoidal 60 Hz magnetic field on free radical production, degranulation, and viability in human neutrophils. Exposure of unstimulated human neutrophils to the magnetic field did not affect the functions examined. When cells were also stimulated with PMA, exposure to a 22 mT, 60 Hz magnetic field induced significant increases in superoxide anion production of 26.5% and in β-glucuronidase release of 53%. Release of lysozyme and lactate dehydrogenase was unchanged by the magnetic field, whether the cells were stimulated or not.

Stimulation of Src family protein-tyrosine kinases as a proximal and mandatory step for SYK kinase-dependent phospholipase Cgamma2 activation in lymphoma B cells exposed to low energy electromagnetic fields

Unknown authors · 1998

Researchers exposed DT40 lymphoma B cells to low energy electromagnetic fields and measured inositol phospholipid turnover. PLC-gamma2-deficient cells and cells with SH2 domain mutant PLC-gamma2 did not show increased IP3 levels after EMF exposure. SYK-deficient cells lacked PLC-gamma2 activation, and the C-terminal SH2 domain of SYK was essential. LYN-deficient cells did not show enhanced inositol phospholipid turnover, but introduction of wild-type fyn restored responsiveness. The results indicate EMF-induced PLC-gamma2 activation is mediated by LYN-regulated stimulation of SYK downstream of LYN and upstream of PLC-gamma2.

Electromagnetic field-induced stimulation of Bruton's tyrosine kinase

Unknown authors · 1998

Researchers exposed DT40 lymphoma B-cells to low energy electromagnetic fields and observed activation of PLC-γ2 and increased inositol phospholipid turnover. PLC-γ2 activation was mediated by stimulation of Bruton's tyrosine kinase (BTK), which acts downstream of LYN kinase and upstream of PLC-γ2. BTK-deficient B-cells did not show enhanced PLC-γ2 activation in response to EMF, but introducing the wild-type human btk gene restored EMF responsiveness. The authors conclude that BTK exerts a pivotal and mandatory function in initiation of EMF-induced signaling cascades in B-cells.

Bruton's tyrosine kinase activity and inositol 1,4,5-trisphosphate production are not altered in DT40 lymphoma B cells exposed to power line frequency magnetic fields

Unknown authors · 1998

Researchers used BTK-deficient DT40 B cells reconstituted with the human btk gene to test whether a 1-gauss 60-Hz electromagnetic field alters inositol 1,4,5-trisphosphate production. Blinded exposures with anti-IgM treatment as a positive control showed no significant effect of the field on inositol 1,4,5-trisphosphate production. The researchers also evaluated BTK activation in wild-type DT40 cells and found that while pervanadate activated BTK in a dose- and time-dependent manner, detection of BTK activation depended on the kinase buffer. Using cells from the original investigators, no evidence supported the hypothesis that the magnetic field had a causal effect on protein-tyrosine kinase activities affecting inositol 1,4,5-trisphosphate production.

Protein kinase C activity following exposure to magnetic field and phorbol ester

Unknown authors · 1998

Researchers examined the separate and combined effects of 60 Hz magnetic fields and a phorbol ester on PKC activity in HL60 cells. Exposure to a 1.1 mT magnetic field alone or combined with 2 microM PMA for 1 h did not enhance PKC activity. In a second experiment, cells preexposed to 50 nM PMA for 45 min then exposed to both PMA and magnetic field for 15 min showed a greater decrease in cytosolic PKC activity and a larger increase in membrane activity than PMA treatment alone or PMA with sham exposure. The authors concluded that magnetic fields may act synergistically on an already activated pathway.

[Levels of immunoglobulin and subpopulations of T lymphocytes and NK cells in men occupationally exposed to microwave radiation in frequencies of 6-12 GHz].

Dmoch A, Moszczynski P · 1998

The effect of ultrahigh-frequency radiation on adaptation thresholds and the damages to blood system cells

Obukhan KI · 1998

Natural killer cell activity reduced by microwave exposure during pregnancy is mediated by opioid systems.

Nakamura et al. · 1998

Researchers exposed pregnant rats to microwaves at 2 mW/cm2, 2450 MHz for 90 minutes and measured natural killer cell activity and beta-endorphin levels. Microwave exposure raised colonic temperature and increased beta-endorphin in blood and anterior pituitary but did not change corticosterone. Naloxone administered before exposure increased natural killer cell activity and beta-endorphin in blood and placenta of pregnant rats.

[Stimulation of production of tumor necrosis factor by murine macrophages when exposed in vio and in vitro to weak electromagnetic waves in the centimeter range].

Novoselova ET, Fesenko EE. · 1998

Researchers studied whether weak electromagnetic waves in the centimeter range could affect tumor necrosis factor production in macrophages from mice. Whole-body microwave irradiation of male NMRI mice, exposure of macrophages in vitro, and irradiation of culture medium with 8.15-18 GHz at a power density of 1 microW/cm2 each caused a significant enhancement of tumor necrosis factor production in peritoneal macrophages.

DNA damage in Molt-4 T- lymphoblastoid cells exposed to cellular telephone radiofrequency fields in vitro

Phillips et al. · 1998

Researchers exposed Molt-4 T-lymphoblastoid cells in vitro to pulsed radiofrequency signals at cellular telephone frequencies of 813.5625 MHz (iDEN® signal) and 836.55 MHz (TDMA signal) to detect DNA damage. The alkaline comet assay was used to measure DNA single-strand breaks in exposed cell cultures compared to sham-exposed cultures. At an SAR of 24 μW g−1, exposure to the iDEN® signal for 2 h and 21 h significantly increased DNA damage, while at 2.4 μW g−1 the same signal significantly decreased DNA damage. The researchers concluded that the data indicate a need to study the effects of exposure to RF signals on direct DNA damage and on the rate at which DNA damage is repaired.

Intracellular calcium signaling by Jurkat T-lymphocytes exposed to a 60 Hz magnetic field

Unknown authors · 1997

Researchers studied intracellular calcium signaling in Jurkat E6-1 human T-leukemia cells during and after exposure to a 60 Hz magnetic field. Cells were labeled with Fluo-3, stimulated with anti-CD3 antibody, and analyzed by flow cytometry for calcium-dependent fluorescence.

Skin changes in "screen dermatitis" versus classical UV- and ionizing irradiation-related damage-- similarities and differences

Unknown authors · 1997

The authors conducted a literature study comparing skin changes in screen dermatitis with those from UV light or ionizing radiation. Screen dermatitis patients had a much higher number of mast cells. The most remarkable cellular change was the disappearance of Langerhans cells, which also occurs after UV or ionizing radiation.

The psychosocial work environment and skin symptoms among visual display terminal workers: a case referent study

Unknown authors · 1997

From an initial questionnaire study among 4943 office workers, 163 VDT workers were selected for a case referent study of facial skin symptoms. The data comprise a self-administered questionnaire filled out by 149 subjects and interviews with representatives of the organizations concerned. Psychosocial conditions, especially lack of social support from co-workers, were associated with an increased risk of reporting skin symptoms. Stratification by sex showed that the associations between some psychosocial factors and health differed between men and women. The results indicate that there might be an interaction between psychosocial factors and electric fields in the workplace which increases the risk of reporting skin symptoms.

Proliferation and cytogenetic studies in human blood lymphocytes exposed in vitro to 2450 MHz radiofrequency radiation.

Vijayalaxmi, Mohan, N, Meltz, ML, Wittler, MA, · 1997

Millemetre waves inhibit the synergistic effect of calcium ionophore A23187 and phorbol ester in neutrophil respiratory burst

Safronova VG et al. · 1997

Effects of high-frequency electromagnetic fields on human lymphocytes in vitro.

Antonopoulos A, Eisenbrandt H, Obe G, · 1997

Human peripheral lymphocytes were incubated in the presence of high-frequency electromagnetic fields of 380, 900 and 1800 MHz. The measured endpoints were cell cycle progression and the frequencies of sister-chromatid exchanges. No differences between treated and control cultures could be found.