Cemil Sert

Oxidative DNA damage in rats exposed to extremely low frequency electro magnetic fields

Extremely low frequency (ELF) electromagnetic field (EMF) is thought to prolong the life of free radicals and can act as a promoter or co-promoter of cancer. 8-hydroxy-2′-deoxyguanosine (8OHdG) is one of the predominant forms of radical-induced lesions to DNA and is a potential tool to asses the cancer risk. We examined the effects of extremely low frequency electro magnetic field (ELF-EMF) (50 Hz, 0.97 mT) on 8OHdG levels in DNA and thiobarbituric acid reactive substances (TBARS) in plasma. To examine the possible time-dependent changes resulting from magnetic field, 8OHdG and TBARS were quantitated at 50 and 100 days. Our results showed that the exposure to ELF-EMF induced oxidative DNA damage and lipid peroxidation (LPO). The 8OHdG levels of exposed group (4.39±0.88 and 5.29±1.16 8OHdG/dG.105, respectively) were significantly higher than sham group at 50 and 100 days (3.02±0.63 and 3.46±0.38 8OHdG/dG.105) (p<0.001, p<0.001). The higher TBARS levels were also detected in the exposure group both on 50 and 100 days (p<0.001, p<0.001). In addition, the extent of DNA damage and LPO would depend on the exposure time (p<0.05 and p<0.05). Our data may have important implications for the long-term exposure to ELF-EMF which may cause oxidative DNA damage.

The preventive effect on bone loss of 50-Hz, 1-mT electromagnetic field in ovariectomized rats

Abstract. Osteoporosis is a common health problem, especially in the elderly and in women after menopause. Although there are some treatment methods, they impose serious side effects. Recently, the use of an electromagnetic field (EMF) has been a promising candidate for better treatment of osteoporosis. In the present study, we investigated the preventive effects of low-frequency (50 Hz), low-intensity (1 mT), and long-term (6 weeks) EMF on bone loss in ovariectomized rats. We used 18 female albino Wistar rats (8 unexposed and 10 exposed) to assess the effect of EMF. We examined the mineralization and the morphology of the tibia in control and EMF-exposed rats. The cortical thickness of the tibia was increased in EMF-exposed rats (P < 0.002). The levels of Na and K in the tibia were significantly increased in rats exposed to EMF (P < 0.001; P < 0.002, respectively). We also observed an increased blood alkaline phosphatase (ALP) level after EMF exposure (P < 0.05). No significant differences in the levels of Ca, Mg, Li, or creatine were found between the exposed and unexposed groups. Our data support the notion that an EMF may prove to be an effective treatment method for osteoporosis and other abnormalities related to bone loss.

Intracellular Ca2+ levels in rat ventricle cells exposed to extremely low frequency magnetic field

Objective: Electromagnetic fields can affect intracellular Ca2+ levels. The aim of this study was to determine the changes intracellular Ca2+ concentration in cardiac ventricle cells of rats exposed to 0.25 mT (2.5 Gauss) magnetic field. Methods: Forty-five male rats were introduced to this study. The rats were divided into three groups: control, sham, and experiment. The experimental group was exposed to 0.25 mT extremely low frequency (ELF) magnetic field for 14 days, 3 h/day. The sham group was treated like the experimental group, except for elf-magnetic field exposure. The control group was not subjected to anything and differed from the experimental group and sham group. In the end of experiment, rats were sacrificed, cardiac tissue was removed, and these were fixed in 10% neutral formalin. Then, ventricular cells were stained by Alizarin red staining method. Results: In the light microscopic examinations of control groups, in myofibril structures between groups, changes were not observed. In myofibril regions of the experimental group compared to other groups, increased heterogen Ca2+ accumulations were found. Conclusion: ELF magnetic fields are used in daily life. The results of this study show that intracellular Ca2+ accumulation in cardiac ventricles can increase in rats exposed to ELF magnetic field.

The Effects of Electromagnetic Fields on the Ultrastructure of Heart

El uso y la comodidad de los aparatos electricos en nuestra vida cotidiana cada vez mas son causa de efectos perjudiciales debido a los campos electromagneticos(CEM).El objetivo de este estudio fue investigar el efecto de los CEM sobre la ultraestructura del corazon en ratas. Fueron utilizadas 45ratas Sprague Daw ley, con peso entre 260 y 280gramos. Las ratas fueron divididas en 3 grupos: control (n: 15); Sham (n:15), y grupo expuesto a CEM (n:15) durante 14 dias,3 horas por dia. Se aplico niveles de 2,5gaussal grupo expuesto a CEM, mientras que el grupo de tratamiento simulado en el mismo entorno en jaulas plexiglas se mantuvo durante14 dias3 horas dia, sin exposicion a campo electromagnetico. Grupo control alimentado en jaulas normales durante 14 dias con ciclo luz/oscuridad de 14/10.Al termino de dos semanas las ratas fueron sacrificadas por medio de anestesia Ketalar 50mg/kg y el tejido del corazon fijado engluteraldehido al 2,5. Se realizo seguimiento de rutina con correspondiente evaluacion de microscopia electronica. Las estructuras mitocondriales y celular es observadas en todos los grupos eran normales. No se observo perdida miofibrilar, tampoco aumento del volumen mitocondrial ni dilatacion del reticulo endoplasmico lisoocristalysis. No se observo degeneracion de los discosintercaladoso apoptosis de nucleo. Por lo tanto,y como resultado de nuestro estudio no encontramos diferencias entre los grupos control y CEM.

Comparison of intracompartmental pressures in a rabbit model of open and closed tibial fractures: An experimental study

We compared the intracompartmental pressures (ICPs) of open and closed tibial fractures with the same injury pattern in a rabbit model. In all, 20 six-month-old New Zealand White male rabbits were used. They were randomised into two equal groups of ten rabbits; an open fracture group (group 1) and a closed fracture group (group 2). Each anaesthetised rabbit was subjected to a standardised fracture of the proximal half of the right tibia using a custom-made device. In order to create a grade II open fracture in group 1, a 10 mm segment of fascia and periosteum was excised. The ICP in the anterior compartment was monitored at six-hourly intervals for 48 hours. Although there was a statistically significant difference in ICP values within each group (both p < 0.001), there was no significant difference between the groups for all measurements (all p ≥ 0.089). In addition, in both groups there was a statistically significant increase in ICP within the first 24 hours, whereas there was a statistically significant decrease within the second 24 hours (p < 0.001 for both groups). We conclude that open tibial fractures should be monitored for the development of acute compartment syndrome to the same extent as closed fractures.

The effect of 2 different surgical methods on intracompartmental pressure value in tibial shaft fracture: An experimental study in a rabbit model

BACKGROUND Intracompartmental pressure (ICP) monitoring is a widely used modality, particularly after intramedullary nailing of tibial shaft fractures. It was hypothesized that ICP value in fracture fixed with Ilizarov circular fixator (ICF) might be lower than in fracture fixed with intramedullary pin (IMP). The present study is a comparison of ICP value in tibial fractures in a rabbit model fixed with ICF and IMP. METHODS Twenty male New Zealand White rabbits were randomly divided into 2 groups of equal size: ICF group (Group 1) and IMP group (Group 2). Under anesthesia, half of proximal part of the right tibia of all rabbits was fractured. Tibial fractures were fixed with ICF in Group 1 and IMP in Group 2. ICP values were monitored at 6-hour intervals for 48 hours. RESULTS There was statistically significant difference in ICP value between groups (p<0.001). While there was statistically significant increase in ICP values 24 hours post surgery, there was statistically significant decrease during second 24 hours following surgery. Most importantly, ICP values of ICF group were significantly lower than those of IMP group at 30, 36, and 42 hours post surgery (p<0.05). CONCLUSION At 24th hour after fixation, ICP values measured in ICF group were lower compared with those of IMP group. These results indicate that use of ICF in tibial fractures provides additional decompression in the anterior compartment. In light of these findings, ICF may be preferable for treatment of tibial fractures with high risk for compartment syndrome.