Aysın Pınar Türkmen

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.

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.

Effect of mercury vapor inhalation on rat ovary: Stereology and histopathology.

Mercury, an environmental contaminant, is a risk factor for health in whole living organisms. In this study, we investigated whether mercury vapor (HgO) inhalation has an effect on rat ovary.

Effects of melatonin on diclofenac sodium treated rat kidney: a stereological and histopathological study

Abstract Objective: In this study, we aimed to investigate the effect of diclofenac sodium (DS) and melatonin (MEL) on kidney of the prenatally administered rats. Materials and methods: Pregnant rats were divided into the control, physiological saline, DS, and DS + MEL groups. All injections were given beginning from the 5th day after mating to the 15th day of the pregnancy. Physical dissector and Cavalieri principle were used to estimate the numerical density and total number of glomeruli and the volumetric parameters of kidney, respectively. Results: Our stereological results indicated that DS application during the pregnancy lead to decrease in the mean volume, numerical density, and total number of the glomeruli (p < 0.05). In addition, we determined that usage of the MEL with the DS caused increases in the mean volume, numerical density, and total number of the glomeruli (p < 0.05). So, there was no significant difference in terms of the any parameter between the CONT and DS + MEL groups (p > 0.05). Light microscopic investigation showed congestion in blood vessels and shrinkage of the Bowmans space in the DS group. Moreover, there was degeneration in nephrons including glomerulosclerosis and tubular defects, and an increase in the connective tissue in the kidneys of the DS-treated group. However, usage of the MEL with the DS caused preventing of these pathological alterations in the kidney. Discussion: We suggested that DS might lead to adverse effects in the kidneys of the rats that are prenatally subjected to this drug. Fortunately, these adverse effects can be prevented by the melatonin supplementation.

Effects of prenatal exposure to diclofenac sodium and saline on the optic nerve of 4- and 20-week-old male rats: a stereological and histological study

Abstract We investigated the effects of diclofenac sodium (DS) on development of the optic nerve in utero. Pregnant female rats were separated into three groups: control, saline treated and DS treated. Offspring of these animals were divided into 4-week-old and 20-week-old groups. At the end of the 4th and 20th weeks of postnatal life, the animals were sacrificed, and right optic nerves were excised and sectioned for ultrastructural and stereological analyses. We demonstrated that both DS and saline produced structural and morphometric changes in the total axon number and density of axons, but decreased the myelin sheath thickness in male optic nerves. All ultrastructural and morphometric features were well developed in 20-week-old rats. We showed that development of the optic nerve continues during the early postnatal period and that some compensation for exposure to deleterious agents in utero may occur during early postnatal life.

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.

Effects of prenatal diclofenac sodium exposure on newborn testis: a histomorphometric study.

Diclofenac sodium (DS) is used primarily to treat fever and to alleviate pain and inflammation. We investigated the effects of DS exposure during gestation on the testes of rat pups to investigate the safety of its use during the prenatal period. Pregnant rats were separated into control, saline, low dose, medium dose and high dose groups. DS was given between weeks 15 and 21 of gestation. Total numbers of spermatogonia and Sertoli cells were counted in the testes of 7-day-old male rats using the physical disector method. By the end of the study, the total number of Sertoli cells was decreased significantly in a dose dependent manner in the medium and high dose groups compared to controls. No significant differences were found in the total number of spermatogonia in the control, saline and low dose DS groups. Medium and high dose DS administration reduced the total number of spermatogonia compared to other groups. We suggest that prenatal administration of DS can cause deleterious effects on the testis development, especially in high doses.

A stereological and histopathological study of the effects of exposure of male rat testes to mercury vapor

Mercury is ubiquitous in the environment; it is an occupational pollutant and a potential toxicant. We investigated the effects of exposure of rat testes to mercury vapor (Hg0). Twelve male rats were divided into two groups of six: the rats of the Hg0 group were exposed to mercury (1 mg/m3/day) in a chamber for six weeks; the control group rats were housed under the same conditions without exposure to Hg0. After the experimental period, the testes were removed, sections of testis were evaluated histopathologically after hematoxylin and eosin staining, and stereologically using the Cavalieri principle and optical fractionator methods. We found significant decreases in the total volume of testis, diameters of seminiferous tubules and total volume of seminiferous tubules. Significant decreases were detected in the numbers of Sertoli cells, spermatogonia, spermatocytes and spermatids of the Hg0 group compared to the control group. In the Hg0 exposed group, spermatogenic cells were degenerated and seminiferous tubules were atrophied.

The role of growth factors in nerve regeneration

Nerve injuries result in functional loss in the innervated organ or body parts, and recovery is difficult unless surgical treatment has been done. Different surgical treatments have been suggested for nerve repair. Tissue engineering related to growth factors has arisen as an alternative approach for triggering and improving nerve regeneration. Therefore, the aim of this review is to provide a comprehensive analysis related to growth factors as tools for optimizing the regeneration process. Studies and reviews on the use of growth factors for nerve regeneration were compiled over the course of the review. According to literature review, it may be concluded that growth factors from different sources present promising treatment related to nerve regeneration involved in neuronal differentiation, greater myelination and axonal growth and proliferation of specific cells for nerve repair.

Embryology of the Peripheral Nerves

Peripheral nerves are organs that reach all tissues by doing complex branching and serve communication such as integrity and interaction between axons and peripheral organs. All of these functions are directly related to the development of peripheral nerves. Because of ethical reasons as well as limited conditions, it is quite difficult to find human nerve samples in fetuses. Therefore, most of the studies about this topic were carried out on experimental animals. This chapter critically overviews the main developmental stages of axons as well as Schwann cells and connective tissue components of peripheral nerves. Because adequate knowledge on the developmental features of peripheral nerves and their basic components is still insufficient, this review can be helpful for treatment approaches relevant to nerve repair and regeneration.