Sıddık Keskin

Effects of 900-MHz electromagnetic field emitted from cellular phone on brain oxidative stress and some vitamin levels of guinea pigs

This study was designed to demonstrate the effects of 900-MHz electromagnetic field (EMF) emitted from cellular phone on brain tissue and also blood malondialdehyde (MDA), glutathione (GSH), retinol (vitamin A), vitamin D(3) and tocopherol (vitamin E) levels, and catalase (CAT) enzyme activity of guinea pigs. Fourteen male guinea pigs, weighing 500-800 g were randomly divided into one of two experimental groups: control and treatment (EMF-exposed), each containing seven animals. Animals in treatment group were exposed to 890- to 915-MHz EMF (217-Hz pulse rate, 2-W maximum peak power, SAR 0.95 w/kg) of a cellular phone for 12 h/day (11-h 45-min stand-by and 15-min spiking mode) for 30 days. Control guinea pigs were housed in a separate room without exposing EMF of a cellular phone. Blood samples were collected through a cardiac puncture and brains were removed after decapitation for the biochemical analysis at the end of the 30 days of experimental period. It was found that the MDA level increased (P<0.05), GSH level and CAT enzyme activity decreased (P<0.05), and vitamins A, E and D(3) levels did not change (P>0.05) in the brain tissues of EMF-exposed guinea pigs. In addition, MDA, vitamins A, D(3) and E levels, and CAT enzyme activity increased (P<0.05), and GSH level decreased (P<0.05) in the blood of EMF-exposed guinea pigs. It was concluded that electromagnetic field emitted from cellular phone might produce oxidative stress in brain tissue of guinea pigs. However, more studies are needed to demonstrate whether these effects are harmful or/and affect the neural functions.

The Correlation of Serum Trace Elements and Heavy Metals with Carotid Artery Atherosclerosis in Maintenance Hemodialysis Patients

Changes in essential trace elements and heavy metals may affect the atherosclerotic state of patients on maintenance hemodialysis (HD). The aim of the study was to evaluate the relation between the serum levels of some trace elements and heavy metals (iron, zinc, manganese, copper, magnesium, cobalt, cadmium, lead, and copper/zinc ratio) and carotid artery intima–media thickness (CIMT) in HD patients. Fifty chronic HD patients without known atherosclerotic disease and 48 age- and sex-matched healthy individuals were included in the study. The serum levels of trace elements (iron, zinc, manganese, copper, and magnesium) and heavy metals (cobalt, cadmium, and lead) were measured by Atomic Adsorption Spectrophotometer (UNICAM-929). CIMT was assessed by carotid artery ultrasonography. The serum levels of iron, zinc, and manganese were lower; levels of copper, magnesium, cobalt, cadmium, lead, and copper/zinc ratio were higher in HD patients compared to controls. CIMT in HD patients were higher than the control group (0.64 ± 0.11 vs 0.42 ± 0.05, p < 0.001). There was a significant negative correlation between CIMT and serum levels of zinc (r = −0.70, p < 0.01), iron (r = −0.71, p < 0.01), and manganese (r = −0.47, p < 0.01), while there was a significant positive correlation between CIMT and serum levels of copper (r = 0.63, p < 0.01), magnesium (r = 0.77, p < 0.01), cobalt (r = 0.63, p < 0.01), cadmium (r = 0.48, p < 0.01), lead (r = 0.38, p < 0.01), and copper/zinc ratio (r = 0.68, p < 0.01). A linear regression analysis showed that serum levels of magnesium, cadmium, lead, and copper/zinc ratio were still significantly and positively correlated with CIMT. We propose that copper/zinc ratio, magnesium and toxic metals cadmium and lead are independent determinants of CIMT in maintenance HD patients without known atherosclerotic disease.

Factor Analysis Scores in a Multiple Linear Regression Model for the Prediction of Carcass Weight in Akkeci Kids

Abstract Keskin, S., Daskiran, I. and Kor, A. 2007. Factor analysis scores in a multiple linear regression model for the prediction of carcass weight in Akkeci kids. J. Appl. Anim. Res., 31: 201–204. In this study, the relationships between carcass weight and 10 body measurements (slaughter weight, withers height, body length, chest depth, chest width, chest circumference, leg circumference, leg width, leg length and rump width) were examined through factor and multiple linear regression analyses. It was observed that three factors e.g. Form, Circumference and Wideness had significant effects on carcass weight and these factors together accounted for 83.9% of variation in carcass weight.

Oxidative DNA damage correlates with carotid artery atherosclerosis in hemodialysis patients.

Oxidative stress is accepted as a nonclassical cardiovascular risk factor in chronic renal failure patients. The aim of this study was to evaluate the relation between oxidative DNA damage (8‐hydroxy‐2′‐deoxyguanosine/deoxyguanosine [8‐OHdG/dG] ratio), oxidative stress biomarkers, antioxidant enzymes, and carotid artery intima‐media thickness (CIMT) in hemodialysis (HD) patients. Forty chronic HD patients without known atherosclerotic disease and 48 age‐ and sex‐matched healthy individuals were included in the study. Plasma malondialdehyde (MDA) levels and 8‐OHdG/dG ratio were determined as oxidative stress markers. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were measured as antioxidants. CIMT was assessed by carotid artery ultrasonography. 8‐OHdG/dG ratios and MDA levels were higher; SOD and GPx activities were lower in HD patients compared to controls. HD patients had significantly higher CIMT compared to controls (0.61 ± 0.08 vs. 0.42 ± 0.05, p < 0.001). There was a significant positive correlation between CIMT and 8‐OHdG/dG ratio (r = 0.57, p < 0.01) and MDA levels (r = 0.41, p < 0.01), while there was a significant negative correlation between CIMT and SOD (r = −0.47, p < 0.01) and GPx levels (r = −0.62, p < 0.01). It is firstly demonstrated that CIMT is positively correlated with oxidative DNA damage in HD patients without known atherosclerotic disease.

Estimation of human daily boron exposure in a boron-rich area.

Although, the safe limits of human daily boron (B) exposure are not absolutely clear, there is a growing interest in B and its effects on human health. The aim of the present study was to estimate daily B exposure in 66 males in Turkey living in a B-rich area using water containing at least 2 mg/l boron, with an average age of 38.55 (se 1.66) years and an average number of years of residence in the B-rich area of 35.89 (se 1.73). Another group of males (n 57), living in the city centres of Balikesir and Ankara, were taken as controls; the average age and number of years of residence for this group were 29.44 (se 1.43) and 10.26 (se 1.83) years, respectively. As it is assumed that the B level in urine reflects daily B exposure, the amount of urinary B of both the study and control groups was analysed by using an inductively coupled plasma optical emission spectrometry (ICP-OES) technique. The average daily B exposure value was calculated as 6.77 (se 0.47) mg in the study group and 1.26 (se 0.1) mg in the controls. The results of this study are expected to contribute to creating a reference value for a safe daily B exposure.

Determination of Factors Influencing Birth Weight Using Regression Tree (RT) Method

Abstract Eyduran, E., Karakus K, Keskin S. and Cengiz F. 2008. Determination of factors influencing birth weight using regression tree (RT) method. J. Appl. Anim. Res., 34: 109–112. This study was conducted to evaluate the effects of genotype, sex, birth type and year and dam age on birth weight by applying regression tree method using 101 Karakas and 103 Norduz lambs raised at Research and Application Farm of the Faculty of Agriculture, Yuzuncu Yil University, Van, Turkey. The effect of sex on single-lambs was significant, whereas, genotype had a significant effect on twin-lambs. The heaviest mean birth weight was obtained by single-male lambs, but twin-lambs born by dam of 2, 3 and 6 years age in the Norduz breed had the lowest mean birth weight.

Use of factor analysis scores in multiple linear regression model for determining relationships between milk yield and some udder traits in goats

Abstract Keskin, S., Kor, A. and Karaca, S. 2007. Use of factor analysis scores in multiple linear regression model for determining relationships between milk yield and some udder traits in goats. J. Appl. Anim. Res., 31: 185–188. In present study, the relationships between daily milk yield (DMY) and 10 udder traits (upper height, bottom height, depth, width, circumference, left and right teat length, left and right teat circumference, teat angle) were examined by using of factor analysis scores in multiple linear regression model. Four factors (teat, udder and height measurements and teat angle) with eigenvalues greater than 1 were selected as independent or explanatory variables and used for multiple linear regression analysis. It was found that four factors had significant effects on daily milk yield and these factors together accounted for 75.4% of variation in daily milk yield.

The Investigation of Relationships Between Some Fruit and Kernel Traits with Canonical Correlation Analysis in Ankara Region Walnuts

Canonical correlation analysis is a multivariate technique, which is employed to examine relationships between two variable sets, each of that consist of two or more variables. In the analysis, by maximizing the relationships between two sets, it is aimed to obtain new variables called as canonical variates that formed by linear combinations of the original variables for each sets. In this study, it is aimed to examine the relationships between some fruit and kernel characteristics of Ankara region walnuts. Thus, the following eight traits Fruit Length (mm), Fruit Width (mm) Fruit Height (mm) Fruit Weight (g), Shell Thickness (mm), Kernel Weight (g), Kernel Ratio (%) and Filled-firm Kernel Ratio (%) of 364 walnut samples were measured. First five of these characteristics were grouped as X variable and the rest of as Y variable. As a result, the correlation between the first canonical variable pair was found as 0.979 (p < 0.01).ZusammenfassungDie kanonische Korrelationsanalyse ist eine multivariate Methode, die zum Einsatz kommt, wenn der Zusammenhang zwischen zwei Sätzen von Variablen, die jeweils wieder aus zwei oder mehr Variablen bestehen, untersucht werden soll. Um eine maximale Korrelation zwischen den beiden Sätzen von Variablen zu finden, zielt die Varianzanalyse darauf ab, neue Variablen zu erhalten, die kanonische Variablen heißen. Sie werden aus Linearkombinationen der beiden ursprünglichen Sätze an Variablen ermittelt. Es ist Ziel dieser Untersuchung, den Grad des Zusammenhangs zwischen einigen Merkmalen von Frucht und Kern (Walnuss) von Walnussbäumen aus der Region um Ankara zu bestimmen. In diesem Zusammenhang wurden von 364 Walnussbäumen Proben gesammelt, von denen Frucht-Länge (mm), Frucht-Querschnitt (mm), Frucht-Größe (mm), Fruchtgewicht (g), Schalen-Dicke (mm), Nusskern-Gewicht (g) und Nusskern-Anteil (%) gemessene wurden und es wurde ermittelt, wie stark der Nusskern-Anteil die Frucht ausfüllt (%). Fünf dieser Merkmale wurden als X-Variablen, die restlichen Variablen als Y-Variablen gruppiert. Zwischen dem ersten kanonischen Variablen-Paar wurde als Ergebnis eine Korrelation von 0,979 (p < 0.01) gefunden.

The effect of altitude and climate on the suicide rates in Turkey

Suicide is one of the most important public health problems. There was an association between suicide and several factors such as psychiatric diseases and psychological characteristics, somatic illness, cultural, socioeconomic, familial, occupational and individual risk factors. Also, high altitude and climatic factors including high temperature, cloudiness, more sunshine and low rainfalls were defined as some of these risk factors in the literature. In this study, we aimed to investigate correlation between suicide rates and altitudes of all cities in Turkey and between suicide rates and climatic factors including Rainfall Activity Index, Winter Mean Temperatures, Summer Mean Temperatures and Temperature Difference between January and July previously defined by several authors in the broad series in Turkey. In Turkey, 29865 suicidal deaths occurred in 10 years period between 2006 and 2015. Of them, 21020 (70.4%) were males and 8845 (29.6%) were females. In this study, we found that high altitude above 1500 m, winter median temperature lower than -10 °C and hard temperature changes above 25 °C between winter and summer of settlements were important factors that affected on female suicide rates appropriate to knowledge which defined in previous studies. In conclusion, we suggested that the associations among suicide rates with altitudes and climate should be studied in wider series obtained from different countries for reaching more reliable results.

Gingival thicknesses of maxillary and mandibular anterior regions in subjects with different craniofacial morphologies

Introduction: The aim of this study was to evaluate the mean gingival thicknesses of the maxillary and mandibular anterior regions in subjects with different craniofacial morphologies. Methods: For each dental arch, 128 periodontally healthy orthodontic patients with normal values of maxillary incisor position (1/NA, angle and distance; and 1/SN, angle) and mandibular incisor position (1/NB, angle and distance; and IMPA) were enrolled in the study. Craniofacial morphology of the participants was evaluated in the sagittal (ANB angle) and vertical directions (SN/GoGn angle) on lateral cephalograms. In the sagittal direction, the subjects were divided into 3 groups as Class I, Class II, and Class III. Each group was classified as low angle, normal, or high angle in the vertical direction. Mean gingival thicknesses of the maxillary and mandibular anterior regions were determined by the ratio of the sum of gingival thickness of the relevant teeth, measured by the transgingival probing technique, to the number of teeth. Results: Mean gingival thicknesses of the maxillary anterior region were 1.173 ± 0.61, 1.103 ± 0.207, and 1.130 ± 0.244 mm in the Class I, Class II, and Class III groups and 1.084 ± 0.150, 1.136 ± 0.247, and 1.159 ± 0.249 mm in the low angle, normal, and high angle groups, respectively. Mean gingival thicknesses of the mandibular anterior region were 0.710 ± 0.156, 0.741 ± 0.176, and 0.691 ± 0.157 mm in the Class I, Class II, and Class III groups and 0.705 ± 0.184, 0.701 ± 0.132, and 0.735 ± 0.174 mm in the low angle, normal, and high angle groups, respectively. No significant difference was found between the groups in terms of the mean gingival thicknesses of the maxillary and mandibular anterior regions. Conclusions: There was no significant difference between the groups in terms of the mean gingival thicknesses of the maxillary and mandibular anterior regions. HighlightsMaxillary anterior regions have thick gingival biotype.Mean gingival thickness is less in mandibular anterior region than in the maxillary region.Mandibular anterior region has thin gingival biotype.There is no association between gingival thicknesses of anterior regions and craniofacial morphology.