Mehmet Berköz

Strontium ranelate treatment improves oxidative damage in osteoporotic rat model.

BACKGROUND Osteoporosis is the most common skeletal disorder and is considered a risk of fracture. Most medication used for the treatment of osteoporosis is antiresorptive; however, strontium ranelate (Sr) therapy in postmenopausal women has shown a double effect on resorption and bone formation. In this study, the effect of Sr on status of the oxidative stress and antioxidant defence system was investigated. METHODS Twenty-one adult albino female Wistar rats were used. The animals were randomly assigned into three groups, control (sham operated rats, received saline), OVX (ovariectomized rats), OVX + Sr (4 months later ovariectomy, strontium ranelate treatment was begun and continued for 120 days) each containing 7 animals. Strontium ranelate (500 mg/kg/day) and placebo (saline) were administered via oral gavage. At the end of the treatment, liver and kidney of rats were removed and malondialdehyde (MDA) level, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities were determined by biochemical analysis methods. RESULTS In liver, MDA levels were significantly higher in the OVX and OVX + Sr groups than the control group. GSH-Px activity decreased in OVX group and increased in OVX + Sr group compared with values of control group. CAT activity was increased in the OVX + Sr group when compared to control group. In kidney, MDA level was increased in OVX group. SOD activity was decreased in the OVX + Sr group. GSH-Px activity decreased in OVX group and increased in OVX + Sr group compared with control group. CAT activity increased in the OVX + Sr group when compared to control. CONCLUSION According to our results, Sr has preventive effect on oxidative damage in ovariectomized rats.

Exposure to gamma rays induces early alterations in skin in rodents: mechanical, biochemical and structural responses.

In this study, the effect of gamma rays has been investigated on the normal rat skin using biomechanical, biochemical and histological techniques. Seventeen male Wistar albino rats were divided into two groups (control (n=7) and irradiated (n=10)). The irradiated group was treated with a (60)Co gamma source at a dose of 10Gy at room temperature. Skin biomechanics were measured with tensile test using biomaterial testing machine and maximum load, stiffness, energy absorption capacity, ultimate stress, ultimate strain and elastic modulus were calculated. In the irradiated group, energy, strain and toughness were significantly lower than in the control group (p<0.05). However, strength, displacement, stiffness, stress and elastic modulus were similar to that of the control group (p>0.05). Catalase (CAT) activities and the levels of malondialdehyde (MDA) in the skin of rats were measured using the biochemical methods. MDA levels significantly increased whereas CAT activities decreased in the irradiated group as compared with the control group (p<0.05). Diameters of collagen fibers were measured by transmission electron microscopy. There was no significant difference (p>0.05) between control and irradiated groups for collagen fiber diameter. Thickness of epidermis was significantly lower than the control group. There were no changes in the epidermis between the irradiated group and the control group ultrastructurally. The results of this study show that the gamma irradiation has a significant effect on normal healthy skin.

Association of CYP2B6 G15631T polymorphism with acute leukemia susceptibility

The Cytochrome P450 (CYP) enzymes constitute one of the biggest gene families and play a vital role in the metabolism of endogenous biomolecules, drugs and xenobiotics. One of the members of this family, CYP2B6, plays a very important role in metabolizing carcinogens and medications. CYP2B6G15631T gene polymorphism reduces CYP2B6 enzyme activity. In this study, we aimed to determine whether any association exists between genetic polymorphism in CYP2B6G15631T and individual susceptibility to acute leukemia. Our study group consisted of 80 acute leukemia patients and 100 unrelated healthy volunteers as a control group. 44 of the acute leukemia patients were diagnosed with acute lymphoblastic leukemia (ALL) and 36 patients with acute myeloid leukemia (AML). Genomic DNA was isolated from peripheral blood and genomic DNA samples were assayed for restriction fragment length polymorphism in the CYP2B6 loci by PCR amplification followed by digestion with BsrI. The data were analyzed statistically employing chi-square and logistic regression analyses. The frequencies of GG genotype (wild type) were 40.9%, 50% and 67% in ALL, AML and control groups, respectively. The frequencies of polymorphic GT genotype (heterozygous variant) were found to be 59.1% in ALL patients, 50% in AML patients and 33% in controls. The TT genotype (homozygous variant) was not observed in either control or leukemia cases. Logistic regression analyses showed a significant correlation between the CYP2B6 G15631T polymorphism (GT) and acute leukemia patients (OR=2.481, 95% CI=1.353-4.551, p=0.003). Our findings indicate that GT genotype may be an important genetic determinant for acute leukemias. According to our knowledge, this is the first report of an association between acute leukemia cases and the CYP2B6 G15631T polymorphism.

Determination of Genotoxic Effects of Hookah Smoking by Micronucleus and Chromosome Aberration Methods

Background Use of a hookah (a type of water pipe) is a traditional way of smoking tobacco, particularly in the Middle East. In Turkey, its popularity has been growing in recent years, especially among young people. It is known that cigarette smoking has genotoxic effects and causes mutations, but no comprehensive study has been done on the genotoxic effects of hookah usage, particularly in Turkey. Material/Methods We collected peripheral blood/buccal smear samples from 30 subjects who did not smoke cigarettes but who regularly smoke a hookah an average of 2 times per week, and from 30 control subjects who had never smoked cigarettes or a hookah. Chromosome analyses were performed on the samples obtained from peripheral blood of each individual, 25 metaphase plaques were counted for each, and chromosome/chromatid breakage/gap parameters were evaluated. Micronucleus analysis was done on buccal smear samples and micronucleus/binucleus parameters were investigated by counting 2000 cells of each individual. Results Chromosome breakage ratios were found to be 0.64±0.86 and 0.46±0.71 in the study and control groups, respectively, while chromatid breakage ratios were 0.53±0.83 and 0.53±0.71; fragment ratios were 0.82±1.24 and 0.21±0.49 (p<0.05); and gap ratios were 0.57±0.83 and 0.18±0.53 (p<0.05), respectively. Micronucleus ratio was 6.03±2.06 and 4.43±2.27 (p<0.05) in the study and control groups, respectively, and binucleus ratios were 8.53±3.23 and 12.15±5.18, respectively (p<0.05). Conclusions Results of our study reveal significant statistical differences between the individuals who smoked hookah and those who did not in terms of fragment, gap, micronucleus, and binucleus parameters, suggesting that smoking a hookah may cause genotoxic effects.

Electrophysiological, biochemical and ultrastructural effects of radiotherapy on normal rat sciatic nerve.

Abstract Purpose: The aim of the present study was to evaluate the electrophysiological, biochemical and ultrastructural changes on the rat sciatic nerve after radiotherapy. Material and Methods: Thirty male Wistar albino rats were divided into three groups as: Control group (n = 10), Group I: 3 months after radiotherapy (n = 10), and Group II: 6 months after radiotherapy (n = 10). Groups I and II were irradiated with a 60Co gamma source. A dose of 20 Gy in 10 fractions was applied to Groups I and II. Compound motor action potentials (CMAP) were recorded in all groups. Superoxide dismutase (SOD) and catalase (CAT) activities and malondialdehyde (MDA) levels were measured in the sciatic nerve of rats using the biochemical methods. Ultrastructural changes were determined by electron microscopy. Results: In Groups I and II, the amplitude of CMAP was significantly lower and the latency was significantly higher than that of the control group. There were no significant differences between Groups I and II regarding the CMAP amplitude and latency. The MDA levels were significantly increased, whereas the SOD and CAT activities were significantly decreased in experimental groups when compared with the control group. However, there were no significant changes in these parameters between Groups I and II. Degeneration in myelinated nerve fibers was observed ultrastructurally only in the experimental groups. Significant changes were observed between the control group and experimental groups in terms of ultrastructural myelin grading score and axonal damage score. No significant differences were found between Groups I and II. Conclusions: These findings indicated that the dose of 20 Gy in 10 fractions radiotherapy caused neuropathic damages in normal rat sciatic nerve 3 and 6 months after irradiation.

Is Nasal Polyposis Related to Levels of Serum Vitamin D and Vitamin D Receptor Gene Expression

Background Nasal polyposis (NP) is the most frequent cause of nasal masses. Despite considerable research on the subject, its etiology has not been fully elucidated, and effective treatment methods have not been developed. Some etiological factors causing low or high expression of genes in genetically predisposed individuals may play a role in the pathogenesis of the disease. The purpose of this study was to assess the relation between levels of vitamin D receptor (VDR) gene expression and serum vitamin D with NP. Material/Methods The study included 46 subjects with NP (NP group) and 40 volunteers (control group). Nasal polyp tissue samples were taken from the NP group and nasal mucosa samples were taken from the control group. Levels of VDR gene expression in the tissue samples were assessed using the real-time polymerase chain reaction (RT-PCR) method. Results Mean serum 25(OH)D levels were 13.38±14.08 ng/ml in the NP group and 10.57±6.44 ng/ml in the control group (p=0.249). VDR gene expression was present in 17.5% of the NP group and 3.3% of the control group, and the difference between the 2 groups was statistically significant (likelihood ratio χ2=3.887; p=0.049). Conclusions This is the first study to assess levels of VDR gene expression in subjects with NP. Our results suggest that VDR gene expression may be associated with the pathogenesis or progression of NP.

IRS-2 G1057D polymorphism in Turkish patients with colorectal cancer

Introduction Gene polymorphisms have a broad range of analysis, but are of particular use in molecular medicine due to their potential in revealing the genetic tendency in diseases such as cancer, heart attack etc. These studies basically depend on mutations that can be detected by proper techniques. The genes coding the insulin receptor substrate (IRS) proteins are among the most widely analysed polymorphisms in various cancer types, in which a G1057D mutation is seen. Aim To determine the risk of colon cancer by analysing the IRS-2 gene polymorphism in Turkish patients. Material and methods A total of 161 newly diagnosed colorectal cancer patients were analysed and compared to 197 unrelated healthy controls. A polymerase chain reaction-based restriction fragment length polymorphism method was carried out. Results No differences were observed between the patient and control groups for both allele and genotype frequencies of the IRS-2 G1057D gene. Conclusions Our results demonstrated that IRS-2 G1057D polymorphism is not associated with colorectal cancer in the Turkish population. This research is a preliminary and original study in Turkish patients with colorectal cancer. It also provides population-level genetic data on IRS-2 in the Turkish population. Further studies should be performed on larger number of patients and controls for more reliable results about the genetic tendency in colorectal cancer in Turkey. The study is a collaborative work of different universities and scientists.

Investigation of Glutathion S-Transferase, Adenosine deaminase, Paraoxonase Activities in Liver of Oncorhynchus mykiss Fed with Nucleotide-Yeast Supplemented Diet

In this study, it was evaluated Glutathione S transferase (GST), Adenosine deaminase (ADA), and paraoxonase (PON) activities in liver tissue of Oncorhynchus mykiss fed with nucleotide yeast base protein supplemented diet. Throughout the 60-day period the control group was fed a fish meal based basal diet, and three other groups were fed diets in which 20% (NP 20), 40% (NP 40) and 60% (NP 60) fish meal was substituted with nucleotide (Nu-Pro® (NP) yeast). At the end of experiment, liver tissue GST, PON and ADA activity was increased significantly (P<0.05) in nucleotide-yeast groups when compared to control group.

1800 MHz radio-frequency electromagnetic radiation induces oxidative stress in rat liver, kidney and brain tissues

Mobile phone use has boomed out in recent years with an estimated 4.6 billion subscriptions globally. It has become an integral part of modern telecommunications. In many countries, over 50 % of the population uses mobile phones, and in some parts of the world, mobile phones are the most reliable or the only phones available. These gadgets use radiofrequency waves for transmitting data. The frequency band used for this varies from country to country (1). Generally the GSM (Global System for Mobile Communications) mobile phones use 900/1800 MHz frequency bands (2). Unlike ionizing radiation such as X-rays or gamma rays, radiofrequency fields can neither break chemical bonds nor cause ionization in the human body. Although this fact is true and well known to everyone, the interaction between this radiation and biological system is a major concern (3). The possible health effects of mobile phone radio-frequency electromagnetic radiation (RFEMR) are bothering the whole world because of the uncontrollable growth of the industry over the globe (4).

Advances in current medication and new therapeutic approaches in epilepsy

Epilepsy is a term used to describe the electrohyperactivity disorder of the brain, which affects different areas of the brain and according to that termed as partial and general seizures. Moreover, different neurotransmitters have played major role in the initiation of seizures, and at the same time suppressing the development of chronic epileptic form. The best-known neurotransmitters involved in epilepsy are γ-aminobutyric acid (GABA), glutamate, serotonin, acetylcholine, Endocannabinoid (1-3). Epilepsy can affect people of all ages, all races, different socials and at any time. The prevalence of the disease showed to reach over 50 million, 75% of which live in scarce income countries with little or no access to medical services (4, 5). In Turkey few data have been obtained to estimate the prevalence of epilepsy throughout the country; however, statistical analysis estimated the prevalence of epilepsy in Turkey is 5.3/1.000 which is higher than developed countries. While the lowest prevalence has been reported to be in Japan at 1.5 per 1.000. Table 1 presents the prevalence of epilepsy in Turkey, while Table 2 presents the global prevalence of the seizure in the world according to the data obtained from World Health Organization (WHO) report (6-9). Major causes of the disease are genetic mutation, head injury, and hypoglycemia (10). Despite the fact that, there is no conclusive treatment for epilepsy, many medicinal drugs, and complementary therapies are utilized as alternative treatment to support the health state of the patients according to their ages, health situations, and state of pregnancy (11). However, antiepileptic drugs are neither preventive nor curative; they used to control symptoms of seizures and save the patient’s life. Antiepileptic drugs are the first class of medications used among all alternative treatment; however, risk factors increase once drug intake increased, aging, drug resistance, tolerance and health state (12). Some AEDs are reported to be used not only in epilepsy ABSTRACT