Ömür Gülsüm Deniz

Electromagnetic field and brain development.

Rapid advances in technology involve increased exposures to radio-frequency/microwave radiation from mobile phones and other wireless transmitting devices. As cell phones are held close to the head during talking and often stored next to the reproductive organs, studies are mostly focused on the brain. In fact, more research is especially needed to investigate electromagnetic field (EMF)s effects on the central nervous system (CNS). Several studies clearly demonstrate that EMF emitted by cell phones could affect a range of body systems and functions. Recent work has demonstrated that EMF inhibit the formation and differentiation of neural stem cells during embryonic development and also affect reproductive and neurological health of adults that have undergone prenatal exposure. The aim of this review is to discuss the developing CNS and explain potential impacts of EMF on this system.

Neuroprotective effects of melatonin and omega-3 on hippocampal cells prenatally exposed to 900 MHz electromagnetic fields.

Abstract Purpose: Adverse effects on human health caused by electromagnetic fields (EMF) associated with the use of mobile phones, particularly among young people, are increasing all the time. The potential deleterious effects of EMF exposure resulting from mobile phones being used in close proximity to the brain require particular evaluation. However, only a limited number of studies have investigated the effects of prenatal exposure to EMF in the development of the pyramidal cells using melatonin (MEL) and omega-3 (ω-3). Materials and methods: We established seven groups of pregnant rats consisting of three animals each; control (CONT), SHAM, EMF, EMF + MEL, MEL, EMF + ω-3 and ω-3 alone. The rats in the EMF, EMF + MEL, EMF + ω-3 groups were exposed to 900 MHz EMF for 60 min/day in an exposure tube during the gestation period. The CONT, MEL and ω-3 group rats were not placed inside the exposure tube or exposed to EMF during the study period. After delivery, only spontaneously delivered male rat pups were selected for the establishment of further groups. Each group of offspring consisted of six animals. The optical fractionator technique was used to determine total pyramidal neuron numbers in the rat hippocampal region. Results: The total number of pyramidal cells in the cornu ammonis (CA) in the EMF group was significantly lower than in the CONT, SHAM, EMF + MEL, and EMF + ω-3 groups. No significant difference was observed between the EMF, MEL and ω-3 groups. No difference was also observed between any groups in terms of rats’ body or brain weights. Conclusion: MEL and ω-3 can protect the cell against neuronal damage in the hippocampus induced by 900 MHz EMF. However, further studies are now needed to evaluate the chronic effects of 900 MHz EMF on the brain in the prenatal period.

Inhalation of mercury vapor can cause the toxic effects on rat kidney

Dental amalgam has been used in dentistry as a filling material. The filler comprises mercury (Hg). It is considered one of the most important and widespread environmental pollutants, which poses a serious potential threat for the humans and animals. However, mercury deposition affects the nervous, cardiovascular, pulmonary, gastrointestinal, and especially renal systems. In most animals’ species and humans, the kidney is one of the main sites of deposition of mercury and target organ for its toxicity. In this study, the effects of mercury intake on kidney in rats were searched. For the this purpose; we used 24 adult female Wistar albino rats (200 g in weight) obtained from Experimental Research and Application Center of Atatürk University with ethical approval. Besides, they were placed into a specially designed glass cage. Along this experiment for 45 days, subjects were exposed to (1 mg/m3/day) mercury vapor. However, no application was used for the control subjects. At the end of the experiment, kidney samples were obtained from all subjects and processed for routine light microscopic level and stereological aspect were assessed. Finally, according to our results, mercury affects the histological features of the kidney. That means, the severe effects of mercury has been shown using stereological approach, which is one of the ideal quantitative methods in the current literature. In this study, it was detected that chronic exposure to mercury vapor may lead to renal damage and diseases in an experimental rat model.

Different methods for evaluating the effects of microwave radiation exposure on the nervous system

Microwave radiation (MWR) leads to hazardous effects on he central nervous system (CNS) for both human and animals. The widespread use of mobile phones has increased the risks of health problems in the CNS caused by radiofrequency (RF) electromagnetic fields. To determine these effects various methodological approaches related to neuroscience such as stereology, immunohistochemistry, and electron microscopy have been used. These approaches examine the effects on cells exposed to MWR at the light microscopic and ultrastructural levels, and novel information is obtained. The main aim of this paper is to discuss possible side effects of MWR in the light of current literature with different methodological approaches.

Genotoxic and carcinogenic effects of non-ionizing electromagnetic fields

&NA; New technologies in electronics and communications are continually emerging. An increasing use of these electronic devices such as mobile phone, computer, wireless fidelity connectors or cellular towers is raising questions concerning whether they have an adverse effect on the body. Exposure to electromagnetic fields (EMF) is frequently suggested to have adverse health effects on humans and other organisms. This idea has been reported in many studies. In contrast, the therapeutic effects of EMF on different organs have also been reported. Research findings are inconsistent. This has given rise to very profound discrepancies. The duration and frequency of mobile phone calls and the association observed with various health effects has raised serious concerns due to the frequency with which these devices are used and the way they are held close to the head. The present review assesses the results of in vitro, in vivo, experimental, and epidemiological studies. The purpose of the study is to assess data concerning the carcinogenic and genotoxic effects of non‐ionizing EMF. The major genotoxic and carcinogenic effects of EMF, divided into subsections as low frequency effects and radiofrequency effects, were reviewed. The inconsistent results between similar studies and the same research groups have made it very difficult to make any comprehensive interpretation. However, evaluation of current studies suggests that EMF may represent a serious source of concern and may be hazardous to living organisms. HighlightsPublic concern over the effects of EMF on cancer is growing.In vitro and in vivo experiments concerning ELF and EMF have elicited contradictory results.Epidemiological studies may help us to understand the genotoxic and carcinogenic effects of EMF.Do adverse effects differ depending on the EMF frequency involved?

Controversies on electromagnetic field exposure and the nervous systems of children.

This paper reviewed possible health effects from exposure to low levels of electromagnetic field (EMF) in children, arising from electrical power sources and mobile phones. Overall, the information about effects on developmental processes and cognitive functions is insufficient and further research on children and adolescents is critically needed. New research approaches are required focused on the effects on the developmental processes of children exposed to electromagnetic fields, using consistent protocols. When the current data were considered in detail, it was noted that childrens unique vulnerabilities make them more sensitive to EMFs emitted by electronics and wireless devices, as compared to adults. Some experimental research shows a neurological impact and exposure in humans may lead to the cognitive and behavioral impairments. Because of the proliferation of wireless devices, public awareness of these dangers now is important to safeguard childrens future healthy brain development.

Possible promoting effects of melatonin, leptin and alcar on regeneration of the sciatic nerve

Peripheral nerve injury is a widespread and disabling condition that can impair the individuals daily life. Studies involving medications that may positively affect peripheral nerve regeneration are rare. The aim of this study was to investigate new treatments after peripheral nerve injury using various neuroprotectants, melatonin, alcar and leptin, in the regenerative process in an experimental rat model. Wistar albino rats were randomly divided into eight groups containing equal number of animals. Intraperitoneal injection of melatonin (50mg/kg, for 21days), leptin (1mg/kg, for 21days) and acetyl-l-carnitine (50mg/kg, for six weeks) was performed postoperatively. Histological and electromyographical assessments of the regenerated nerves were performed 12 weeks after surgery. Stereological analysis was performed to estimate myelinated and unmyelinated axon numbers, surface area, myelin thickness and the myelin thickness/axon diameter ratio for each group. The results showed that only alcar has a beneficial effect on the regeneration of unmyelinated axons. Neither melatonin and leptin nor alcar were observed to have any therapeutic effect on the regeneration of myelinated axons. Alcar therapy has a positive effect on the regeneration of unmyelinated fiber in the sciatic nerve. However, the same effect was not observed in myelinated nerve fibers after intraperitoneal application of melatonin and leptin.

Effects of short and long term electromagnetic fields exposure on the human hippocampus

The increasing use of mobile phones may have a number of physiological and psychological effects on human health. Many animal and human studies have reported various effects on the central nervous system and cognitive performance from of exposure to electromagnetic fields (EMF) emitted by mobile phones. The aim of the present study was to evaluate the effects of mobile phones on the morphology of the human brain and on cognitive performance using stereological and spectroscopic methods and neurocognitive tests. Sixty healthy female medical school students aged 18–25 years were divided into a low exposure group (30 subjects, <30 min daily use by the head) and high exposure group (30 subjects, >90 min daily use by the head). Magnetic resonance images (MRI) of the brain analysed on OsiriX 3.2.1 workstation. Neuropsychological tests were performed for each subject. In addition, three dominant specific metabolites were analysed, choline at 3.21 ppm, creatine at 3.04 ppm and N-acetyl aspartate at 2.02 ppm. Analysis of the spectroscopic results revealed no significant difference in specific metabolites between the groups (p > 0.05). There was also no significant difference in terms of hippocampal volume between the groups (p > 0.05). In contrast, the results of the stroop and digit span (backward) neurocognitive tests of high exposure group for evaluating attention were significantly poorer from low exposure group (p < 0.05). Based on these results, we conclude that a lack of attention and concentration may occur in subjects who talk on mobile phones for longer times, compared to those who use phones relatively less.

Effects of folic acid on rat kidney exposed to 900 MHz electromagnetic radiation

Because of increased use of cell phones, the purpose of this study was to investigation of the oxidative damage caused by electromagnetic radiation (EMR) emitted by cell phones and histological and morphometrical determination of the possible protective role of folic acid (FA) in preventing the detrimental effects of EMR on the kidney. Twenty-four adult male Wistar albino rats were divided into control (Cont), EMR, EMR + FA and FA groups, each containing six rats. The EMR and EMR + FA groups were exposed to EMR for 60 min a day over a period of 21 days, while no EMR exposure was applied to the Cont and FA groups. The source of the EMR was an EMR device which emits a digital signal producing 900-MHz frequency radiation. The generator connected to a one-monopole antenna was used in this study and the rats were placed in the plexiglass restrainer at an equal distance from the monopole antenna. Following the experimental period, and after tissue processing, a physical disector-Cavalieri method combination was applied to the sections. The mean volume of the cortex, medulla, proximal and distal tubules increased significantly in the EMR groups compared to the Cont group (p < 0.01). Contrarily, the total number of glomeruli in the EMR group decreased compared to the Cont group (p < 0.01). The protective effects of FA was observed in the kidney (p < 0.05). In conclusion, the 900-MHz EMR leads to kidney damage. FA may exhibit a protective effect against the adverse effects of EMR exposure in terms of the total number of glomeruli.

A concise review of optical, physical and isotropic fractionator techniques in neuroscience studies, including recent developments

Stereology is a collection of methods which makes it possible to produce interpretations about actual three-dimensional features of objects based on data obtained from their two-dimensional sections or images. Quantitative morphological studies of the central nervous system have undergone significant development. In particular, new approaches known as design-based methods have been successfully applied to neuromorphological research. The morphology of macroscopic and microscopic structures, numbers of cells in organs and structures, and geometrical features such as length, volume, surface area and volume components of the organ concerned can be estimated in an unbiased manner using stereological techniques. The most practical and simplest stereological method is the fractionator technique, one of the most widely used methods for total particle number estimation. This review summarizes fractionator methods in theory and in practice. The most important feature of the methods is the simplicity of its application and underlying reasoning. Although there are three different types of the fractionator method, physical, optical and isotropic (biochemical), the logic underlying its applications remains the same. The fractionator method is one of the strongest and best options among available methods for estimation of the total number of cells in a given structure or organ. The second part of this review focuses on recent developments in stereology, including how to deal with lost caps, with tissue section deformation and shrinkage, and discusses issues of calibration, particle identification, and the role of stereology in the era of a non-histological alternative to counting of cells, the isotropic fractionator (brain soup technique).