Induced mitogenic activity in AML-12 mouse hepatocytes exposed to low-dose ultra-wideband electromagnetic radiation

Effect of ultra‑wide‑band electromagnetic pulses on blood‑brain barrier permeability in rats

The restrictive nature of the blood brain barrier (BBB) brings a particular challenge to the treatment of central nervous system (CNS) disorders. The effect of ultra-wide band electromagnetic pulses (UWB-EMPs) on BBB permeability was examined in the present study in order to develop a safe and effective technology that opens the BBB to improve treatment options for CNS diseases. Rats were exposed to a single UWB-EMP at various field strengths (50, 200 or 400 kV/m) and the BBB was examined using albumin immunohistochemistry and Evans blue staining at different time periods (0.5, 3, 6 and 24 h) after exposure. The expression and distribution of zonula occludens 1 (ZO-1) were evaluated using western blotting to identify a potential mechanism underlying BBB permeability. The results showed that the BBB permeability of rats exposed to UWB-EMP increased immediately following UWM-EMP treatment and peaked between 3 and 6 h after UWB-EMP exposure, returning to pre-exposure levels 24 h later. The data suggested that UWB-EMP at 200 and 400 kV/m could induce BBB opening, while 50 kV/m UWB-EMP could not. The levels of ZO-1 in the cerebral cortex were significantly decreased at 3 and 6 h after exposure; however, no change was observed in the distribution of ZO-1. The present study indicated that UWB-EMP-induced BBB opening was field strength-dependent and reversible. Decreased expression of ZO-1 may be involved in the effect of UWB-EMP on BBB permeability.

Repeated exposure to nanosecond high power pulsed microwaves increases cancer incidence in rat

High-power microwaves are used to inhibit electronics of threatening military or civilian vehicles. This work aims to assess health hazards of high-power microwaves and helps to define hazard threshold levels of modulated radiofrequency exposures such as those emitted by the first generations of mobile phones. Rats were exposed to the highest possible field levels, under single acute or repetitive exposures for eight weeks. Intense microwave electric fields at 1 MV m-1 of nanoseconds duration were applied from two sources at different carrier frequencies of 10 and 3.7 GHz. The repetition rate was 100 pps, and the duration of train pulses lasted from 10 s to twice 8 min. The effects on the central nervous system were evaluated, by labelling brain inflammation marker GFAP and by performing different behavioural tests: rotarod, T-maze, beam-walking, open-field, and avoidance test. Long-time survival was measured in animals repeatedly exposed, and anatomopathological analysis was performed on animals sacrificed at two years of life or earlier in case of precocious death. Control groups were sham exposed. Few effects were observed on behaviour. With acute exposure, an avoidance reflex was shown at very high thermal level (22 W kg-1); GFAP was increased some days after exposure. Most importantly, with repeated exposures, survival time was 4-months shorter in the exposed group, with eleven animals exhibiting a large sub-cutaneous tumour, compared to two in the sham group. A residual X-ray exposure was also present in the beam (0.8 Gy), which is probably not a bias for the observed result. High power microwaves below thermal level in average, can increase cancer prevalence and decrease survival time in rats, without clear effects on behaviour. The parameters of this effect need to be further explored, and a more precise dosimetry to be performed.

Pulsed radiofrequency energy accelerates wound healing in diabetic mice

BACKGROUND

Impaired healing is a problematic and common complication of chronic wounds. Although pulsed radiofrequency energy has been used in the treatment of chronic wounds with promising efficacy, its mechanism is still poorly characterized. In this study, the authors used a diabetic mouse model to illustrate the action of pulsed radiofrequency energy on cutaneous wounds and set the stage to begin to understand its mechanism.

METHODS

Full-thickness cutaneous wounds were created in diabetic mice (n = 26). The experimental group (n = 13) was subject to pulsed radiofrequency energy treatment two times per day, whereas the sham group (n = 13) was subjected to sham devices. The rate of wound closure was evaluated by digital analysis of surface area of the wound bed, zone of reepithelialization, and rate of contraction. Mice were euthanized on days 7, 10, 22, and 42 and wounds were evaluated qualitatively and quantitatively by hematoxylin and eosin, Masson's trichrome, and Ki-67 assay for cell proliferation.

RESULTS

In the experimental group, the rate of wound closure was significantly accelerated, particularly beyond day 17. Contraction contributed to the wound healing process rather than reepithelialization. This was also associated with increased granulation tissue that was most prominent by day 22 and with enhanced dermal cell proliferation, with 25 percent and 45 percent Ki-67-positive nuclei on days 10 and 22, respectively, as compared with control animals.

CONCLUSION

These results indicate that pulsed radiofrequency energy accelerates impaired wound healing mainly through wound contraction by means of stimulating cell proliferation, granulation tissue formation, and collagen deposition.

Effect of electromagnetic nanopulses on C. elegans fertility

Electromagnetic nanopulse exposure results in decreased fertility of C. elegans, a well studied, multicellar organism. Experiments indicate that this effect is unlikely to be due to heating. Instead, nanopulses interfere with fertilization or development by an as yet undetermined mechanism. Study of nanopulse exposure of C. elegans could help to understand more generally how living organisms interact with electromagnetic fields.