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Featured researches published by Serdar Colakoglu.


Reproductive Toxicology | 2013

The effect of prenatal exposure to 900-MHz electromagnetic field on the 21-old-day rat testicle

Hatice Hancı; Ersan Odaci; Haydar Kaya; Yuksel Aliyazicioglu; Ibrahim Turan; Selim Demir; Serdar Colakoglu

The aim of this study was to investigate the effect of exposure to a 900-MHz electromagnetic field (EMF) in the prenatal term on the 21-old-day rat testicle. Pregnant rats were divided into control (CG) and EMF (EMFG) groups. EMFG was exposed to 900-MHz EMF during days 13-21 of pregnancy. Newborn CG rats were obtained from the CG and newborn EMFG (NEMFG) rats from the EMFG. Testicles were extracted at postnatal day 21. Lipid peroxidation and DNA oxidation levels, apoptotic index and histopathological damage scores were compared. NEMFG rats exhibited irregularities in seminiferous tubule basal membrane and epithelium, immature germ cells in the lumen, and a decreased diameter in seminiferous tubules and thickness of epithelium. Apoptotic index, lipid peroxidation and DNA oxidation were higher in NEMFG rats than in NCG. 21-day-old rat testicles exposed to 900-MHz EMF in the prenatal term may be adversely affected, and this effect persists after birth.


Biotechnic & Histochemistry | 2015

Pathological effects of prenatal exposure to a 900 MHz electromagnetic field on the 21-day-old male rat kidney

Ersan Odaci; Deniz Unal; Tolga Mercantepe; Zehra Topal; Hatice Hancı; Sibel Türedi; Hüseyin Serkan Erol; Mungan S; Haydar Kaya; Serdar Colakoglu

Abstract We investigated the effects on kidney tissue of 900 megahertz (MHz) EMF applied during the prenatal period. Pregnant rats were exposed to 900 MHz EMF, 1 h/day, on days 13–21 of pregnancy; no procedure was performed on control group pregnant rats or on mothers or newborns after birth. On postnatal day 21, kidney tissues of male rat pups from both groups were examined by light and electron microscopy. Malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione levels also were investigated. Light microscopy revealed some degenerative changes in the tubule epithelium, small cystic formations in the primitive tubules and large cysts in the cortico-medullary or medullary regions in the experimental group. Electron microscopy revealed a loss of peritubular capillaries and atypical parietal layer epithelial cells in the experimental group. Biochemical analysis showed significantly increased MDA levels in the experimental group and decreased SOD and CAT levels. EMF applied during the prenatal period can caused pathological changes in kidney tissue in 21-day-old male rats owing to oxidative stress and decreased antioxidant enzyme levels.


International Journal of Developmental Neuroscience | 2008

Prenatal exposure to a non-steroidal anti-inflammatory drug or saline solution impairs sciatic nerve morphology: a stereological and histological study

Sinan Canan; Abit Aktaş; M. Başak Ulkay; Serdar Colakoglu; Murat Cetin Ragbetli; Mustafa Ayyildiz; Stefano Geuna; Süleyman Kaplan

The toxic effect of non‐steroidal anti‐inflammatory drugs (NSAIDs) during development has been widely investigated. While it has been shown that these drugs impair central nervous development and compromise the neural activity, the effects of these substances on the development of peripheral nerves are still not clarified. In the present study, sciatic nerves withdrawn from three experimental groups of 4‐week‐old rats, prenatally exposed to either saline solution, or diclofenac sodium, and controls not exposed to any substance, were evaluated in terms of axon number, cross‐sectional area of axon and myelin sheet thickness as well as of the ultrastructure of nerve fibers. Comparisons of stereological estimations among these three groups showed that axon number and mean axon cross‐sectional area, but not average myelin sheet thickness, were significantly decreased in rats that were exposed to both diclofenac sodium and also to the saline solution, in comparison of the control group. Electron microscope analysis revealed, in both treated groups, deterioration of myelin sheaths that was more pronounced in rats that were exposed to diclofenac sodium. Altogether, these findings show that the prenatal administration of both diclofenac sodium and saline solution impairs peripheral nervous system development, thus suggesting that this potential teratogenic effect should be also taken into consideration in the clinical use of these substances in pregnant patients.


Toxicon | 2013

Amanitin and phallotoxin concentration in Amanita phalloides var. alba mushroom

Ertugrul Kaya; Ismail Yilmaz; Zeynep Aydin Sinirlioglu; Selim Karahan; Recep Bayram; Kursat Oguz Yaykasli; Serdar Colakoglu; Ayhan Saritas; Zeki Severoglu

Although rarely seen, Amanita phalloides var. alba, a variety of A. phalloides type mushrooms, causes mushroom poisoning resulting in death. Since it is frequently confused with some edible mushrooms due to its white colored cap and macroscopic appearance, it becomes important in toxicological terms. Knowledge of the toxin amount contained in this mushroom type is invaluable in the treatment of cases involving poisoning. In this study, we examined the toxin levels of various parts of the A. phalloides var. alba mushroom growing Duzce region of Turkey. Toxin analyses were carried out for A. phalloides var. alba, which were collected from the forests Duzce region of Turkey in 2011, as a whole and also separately in its spore, pileus, gills, stipe and volva parts. The alpha amanitin, beta amanitin, gamma amanitin, phalloidin and phallacidine analyses of the mushrooms were carried out using the RP-HPLC method. A genetic analysis of the mushroom showed that it had similar genetic characteristics as A. phalloides and was a variety of it. The lowest toxins quantity was detected in spores, volva and stipe among all parts of the mushroom. The maximum amount of amatoxins was measured in the gills. The pileus also contained a high amount of amatoxins. Generally, amatoxins and phallotoxin concentrations were lower as compared to A. phalloides, but interestingly all toxins other than gamma toxin were higher in the spores of A. phalloides var. alba. The amount of toxin in all of its parts had sufficient concentrations to cause death. With this study, the amatoxin and phallotoxin concentrations in A. phalloides var. alba mushroom and in its parts have been revealed in detail for the first time.


Toxicology and Industrial Health | 2015

Amatoxin and phallotoxin concentration in Amanita phalloides spores and tissues.

Ertugrul Kaya; Selim Karahan; Recep Bayram; Kursat Oguz Yaykasli; Serdar Colakoglu; Ayhan Saritas

Most of the fatal cases of mushroom poisoning are caused by Amanita phalloides. The amount of toxin in mushroom varies according to climate and environmental conditions. The aim of this study is to measure α-, β-, and γ-amanitin with phalloidin and phallacidin toxin concentrations. Six pieces of A. phalloides mushrooms were gathered from a wooded area of Düzce, Turkey, on November 23, 2011. The mushrooms were broken into pieces as spores, mycelium, pileus, gills, stipe, and volva. α-, β-, and γ-Amanitin with phalloidin and phallacidin were analyzed using reversed-phase high-performance liquid chromatography. As a mobile phase, 50 mM ammonium acetate + acetonitrile (90 + 10, v/v) was used with a flow rate of 1 mL/min. C18 reverse phase column (150 × 4.6 mm; 5 µm particle) was used. The least amount of γ-amanitin toxins was found at the mycelium. The other toxins found to be in the least amount turned out to be the ones at the spores. The maximum amounts of amatoxins and phallotoxin were found at gills and pileus, respectively. In this study, the amount of toxin in the spores of A. phalloides was published for the first time, and this study is pioneering to deal with the amount of toxin in mushrooms grown in Turkey.


Toxicon | 2014

Clinical importance of toxin concentration in Amanita verna mushroom.

Ismail Yilmaz; Ertugrul Kaya; Zeynep Aydin Sinirlioglu; Recep Bayram; Mustafa Gani Surmen; Serdar Colakoglu

Poisoning from Amanita group of mushrooms comprises approximately 3% of all poisonings in our country and their being responsible for nearly the entire fatal mushroom poisonings makes them important. These mushrooms contain primarily two types of toxins, amatoxins and phallotoxins. Phallotoxins have a more limited toxicity potential and they primarily consist of phalloidin (PHN) and phallacidin (PCN). Amatoxins, on the other hand, are very toxic and they primarily consist of alpha-amanitin (AA), beta-amanitin (BA) and gamma-amanitin (GA). Toxin levels can vary among various species, even among varieties of the same species, of Amanita mushroom family. Revealing the differences between the toxin compositions of the Amanita species that grow in our region may contribute to the clinics of poisonings. Our study aims at showing in detail the toxin levels in various parts of Amanita verna mushroom. A. verna mushrooms needed for toxin analysis were collected from Kozak Plateau near Ayvalik county of Balıkesir, Turkey in April 2013. The mushrooms were divided into their parts as pileus, gills, stripe and volva. Following the procedures required before the analysis, the AA, BA, GA, PHN and PCN levels were measured using the RP-HPLC method. While the lowest level of amatoxin was in the volva of the mushroom, the highest was measured in the gills. This was followed by pileus and stripe where the levels were close to each other. Similarly, the highest level of phallotoxin was measured in the gills. Gamma toxin and phalloidin were at lower amounts than the other toxins. A. verna is frequently confused with edible mushrooms with white caps due to its macroscopic similarity. If just one of them is eaten by mistake by an adult person with no mushroom experience, it can easily poison them. The amount of amatoxin is more as compared to Amanita phalloides and A. phalloides var. alba. Particularly, the AA and BA levels are approximately three times higher, whereas GA levels are lower. Similarly, the level of PCN is approximately four times higher as compared to A. phalloides and A. phalloides var. alba; by contrast, the level of PNH is about a half of theirs. In summary, it can be said that A. verna is a more toxic mushroom than A. phalloides and has a higher rate of mortality. With our study, the amatoxin and phallotoxin concentrations and distribution in A. verna mushrooms were shown in detail for the first time and it would be useful to carry out more similar studies with other members of Amanita family growing in various parts of the world.


International Journal of Radiation Biology | 2016

Disruption of the ovarian follicle reservoir of prepubertal rats following prenatal exposure to a continuous 900-MHz electromagnetic field

Sibel Türedi; Hatice Hancı; Serdar Colakoglu; Haydar Kaya; Ersan Odaci

Abstract The effects on human health of electromagnetic field (EMF) have begun to be seriously questioned with the entry into daily life of devices establishing EMF, such as cell phones, wireless fidelity, and masts. Recent studies have reported that exposure to EMF, particularly during pregnancy, affects the developing embryo/fetus. The aim of this study was therefore to examine the effects of exposure to continuous 900-Megahertz (MHz) EMF applied in the prenatal period on ovarian follicle development and oocyte differentiation. Six pregnant Sprague Dawley rats were divided equally into a non-exposed control group (CNGr) and a group (EMFGr) exposed to continuous 900-MHz EMF for 1 h daily, at the same time every day, on days 13–21 of pregnancy. New groups were established from pups obtained from both groups after birth. One group consisting of female pups from CNGr rats was adopted as newborn CNGr (New-CNGr, n = 6), and another group consisting of female pups from EMFGr rats was adopted as newborn EMFGr (New-EMFGr, n = 6). No procedure was performed on New-CNGr or New-EMFGr rats. All rat pups were sacrificed on the postnatal 34th day, and their ovarian tissues were removed. Follicle count, histological injury scoring and morphological assessment with apoptotic index criteria were performed with sections obtained following routine histological tissue preparation. Follicle count results revealed a statistically significant decrease in primordial and tertiary follicle numbers in New-EMFGr compared to New-CNGr (p < 0.05), while atretic follicle numbers and apoptotic index levels increased significantly (p < 0.05). Histopathological examination revealed severe follicle degeneration, vasocongestion, a low level of increased stromal fibrotic tissue and cytoplasmic vacuolization in granulosa cell in New-EMFGr. Prenatal exposure to continuous 900-MHz EMF for 1 h each day from days 13–21 led to a decrease in ovarian follicle reservoirs in female rat pups at the beginning of the prepubertal period.


Journal of Clinical Neuroscience | 2010

A stereological study of MRI and the Cavalieri principle combined for diagnosis and monitoring of brain tumor volume.

Osman Fikret Sonmez; Ersan Odaci; Orhan Bas; Serdar Colakoglu; Bunyamin Sahin; Sait Bilgic; Süleyman Kaplan

In this study, we aimed to describe the application of the Cavalieri principle for the assessment of tumor volume using MRI without an over-projection/estimation effect. For this purpose, the volume of a patients brain and the brain tumor volume, or the volume of the former tumor region, were estimated preoperatively and postoperatively using a combination of the Cavalieri principle and MRI. The previously described formula was modified for MRI measurements to eliminate the over-estimation effects of imaging. The total brain and tumor volumes estimated using the MRI of a representative patient with glioblastoma multiforme were: preoperative, 1562.46 cm³ and 81.59 cm³, respectively; and postoperative, 1571.72 cm³ and 86.92 cm³, respectively. The mean time to count points for an estimation of brain and tumor volume (or the volume of the former tumor region) were 14 minutes and 3 minutes, respectively. The coefficients of the errors of the estimates for brain and tumor volume (former tumor volume, postoperative) measurements were: preoperative 0.01 and 0.02; and postoperative 0.01 and 0.03, respectively. Our results show that the combination of MRI and the Cavalieri principle can provide an unbiased, direct and assumption-free estimate of the regions of interest. Therefore, the presented method could be applied efficiently without any need for special software, additional equipment or personnel other than that required for routine MRI in daily use.


Biotechnic & Histochemistry | 2016

Effects of prenatal exposure to a 900 MHz electromagnetic field on 60-day-old rat testis and epididymal sperm quality

Ersan Odaci; Hatice Hancı; E Yuluğ; Sibel Türedi; Yuksel Aliyazicioglu; Haydar Kaya; Serdar Colakoglu

We investigated the effects of exposure in utero to a 900 megahertz (MHz) electromagnetic field (EMF) on 60-day-old rat testis and epididymis. Pregnant rats were divided into control (CG; no treatment) and EMF (EMFG) groups. The EMFG was exposed to 900 MHz EMF for 1 h each day during days 13 − 21 of pregnancy. Newborn rats were either newborn CG (NCG) or newborn EMF groups (NEMFG). On postnatal day 60, a testis and epididymis were removed from each animal. Epididymal semen quality, and lipid and DNA oxidation levels, apoptotic index and histopathological damage to the testis were compared. We found a higher apoptotic index, greater DNA oxidation levels and lower sperm motility and vitality in the NEMFG compared to controls. Immature germ cells in the seminiferous tubule lumen, and altered seminiferous tubule epithelium and seminiferous tubule structure also were observed in hematoxylin and eosin stained sections of NEMFG testis. Nuclear changes that indicated apoptosis were identified in TUNEL stained sections and large numbers of apoptotic cells were observed in most of the seminiferous tubule epithelium in the NEMFG. Sixty-day-old rat testes exposed to 900 MHz EMF exhibited altered sperm quality and biochemical characteristics.


Brain Research | 2015

Deleterious impacts of a 900-MHz electromagnetic field on hippocampal pyramidal neurons of 8-week-old Sprague Dawley male rats

Arzu Şahin; Ali Aslan; Orhan Baş; Ayşe İkinci; Cansu Özyılmaz; Osman Fikret Sonmez; Serdar Colakoglu; Ersan Odaci

Children are at potential risk due to their intense use of mobile phones. We examined 8-week-old rats because this age of the rats is comparable with the preadolescent period in humans. The number of pyramidal neurons in the cornu ammonis of the Sprague Dawley male rat (8-weeks old, weighing 180-250 g) hippocampus following exposure to a 900 MHz (MHz) electromagnetic field (EMF) were examined. The study consisted of control (CN-G), sham exposed (SHM-EG) and EMF exposed (EMF-EG) groups with 6 rats in each. The EMF-EG rats were exposed to 900 MHz EMF (1h/day for 30 days) in an EMF jar. The SHM-EG rats were placed in the EMF jar but not exposed to the EMF (1h/day for 30 days). The CN-G rats were not placed into the exposure jar and were not exposed to the EMF during the study period. All animals were sacrificed at the end of the experiment, and their brains were removed for histopathological and stereological analysis. The number of pyramidal neurons in the cornu ammonis of the hippocampus was estimated on Cresyl violet stained sections of the brain using the optical dissector counting technique. Histopathological evaluations were also performed on these sections. Histopathological observation showed abundant cells with abnormal, black or dark blue cytoplasm and shrunken morphology among the normal pyramidal neurons. The largest lateral ventricles were observed in the EMF-EG sections compared to those from the other groups. Stereological analyses showed that the total number of pyramidal neurons in the cornu ammonis of the EMF-EG rats was significantly lower than those in the CN-G (p<0.05) and the SHM-EG (p<0.05). In conclusion, our results suggest that pyramidal neuron loss and histopathological changes in the cornu ammonis of 8-week-old male rats may be due to the 900-MHz EMF exposure.

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Ersan Odaci

Karadeniz Technical University

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Haydar Kaya

Karadeniz Technical University

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Hatice Hancı

Karadeniz Technical University

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Kursat Oguz Yaykasli

Imam Muhammad ibn Saud Islamic University

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Recep Bayram

Abant Izzet Baysal University

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