Browsing by Author "Meral, I."

Now showing 1 - 6 of 6

Effects of 900 Mhz Electromagnetic Field Emitted by Cellular Phones on Electrocardiograms of Guinea Pigs
(Sage Publications Ltd, 2014) Meral, I.; Tekintangac, Y.; Demir, H.
This study was carried out to determine the effects of electromagnetic field (EMF) emitted by cellular phones (CPs) on electrocardiograms (ECGs) of guinea pigs. A total of 30 healthy guinea pigs weighing 500-800g were used. After 1 week of adaptation period, animals were randomly divided into two groups: control group (n=10) and EMF-exposed group (n=20). Control guinea pigs were housed in a separate room without exposing them to EMFs of CPs. Animals in second group were exposed to 890-915MHz EMF (217Hz of pulse rate, 2W of maximum peak power and 0.95wtkg(-1) of specific absorption rate) for 12hday(-1) (11h 45min stand-by and 15min speaking mode) for 30 days. ECGs of guinea pigs in both the groups were recorded by a direct writing electrocardiograph at the beginning and 10th, 20th and 30th days of the experiment. All ECGs were standardized at 1mV=10mm and with a chart speed of 50 mmsec(-1). Leads I, II, III, lead augmented vector right (aVR), lead augmented vector left (aVL) and lead augmented vector foot (aVF) were recorded. The durations and amplitudes of waves on the trace were measured in lead II. The data were expressed as mean with SEM. It was found that 12hday(-1) EMF exposure for 30 days did not have any significant effects on ECG findings of guinea pigs. However, this issue needed to be further investigated in a variety of perspectives, such as longer duration of exposure to be able to elucidate the effects of mobile phone-induced EMFs on cardiovascular functions.
Investigation of a Counteragent for Monensin Toxicity
(Scientific and Technical Research Council of Turkey, 1997) Meral, I.
This experiment was carried out in Veterinary Medicine at Iowa State University, USA. The ability of ryanodine to counteract the toxic effect of monensin was investigated by using adult male guinea-pigs. Heart rate and mean arterial blood pressure were measured. Data were collected every five minutes for one hour after drug injection then averaged. The toxic dose of monensin significantly (P<0.05) decreased the heart rate and mean arterial blood pressure of guinea-pigs. However, decreased heart rate and mean arterial blood pressure caused by monensin were significantly (P<0.05) increased by ryanodine. It is concluded that ryanodine has a potent to be used as a counteragent for monensin poisoning.
Investigation of the Cellular Mechanisms of Actions of Digoxin and Monensin by Using Guinea-Pig Papillary Muscles
(2009) Üstün, R.; Meral, I.
Intensive and dwarfed fruit apple fruit production is getting common for last ten years in Turkey. Modern apple production has brought an important level with the contribution of some private sectors in Karaman, Isparta, Konya, Niǧde and Denizli where apple production is common. It is still not desired level due to improper cultural applications such as irrigation, fertilization and especially in pruning. Among the cultural applications which effect the yield and fruit quality, pruning and training of trees are the most important. Although pruning application is getting common over producers, these applications are still not modern pruning systems as desired. Training and pruning are such a techniques that several factors such rootstock, cultivar, planting density and support systems are need to be considered all together, Among them, pruning is the most important and sophisticated factor. When the producers give enough importance on pruning, they will observe improvements both in yield and fruit quality.
The Nutritional Habits and Relationship Between The Antioxidant Activity and Iron Deficiency Anemia During Pregnancy
(Yuzuncu Yil Universitesi Tip Fakultesi, 2022) Guven, S.; Meral, I.; Kurdoglu, M.; Demir, H.
The aim of this study was to investigate the changes in nutritional habits, and also relationship among oxidative stress, iron deficiency anemia and some antioxidant enzyme activities during pregnancy. Twenty pregnant women in the first trimester, 20 pregnant women in the last trimester and 20 non-pregnant women (control group) were included in the study. The study groups were similar in terms of age and body mass index. None of the participants had any systemic disease or smoked. After having filled out the questionnaire about nutritional habits, the blood samples were collected, and the malondialdehyde (MDA) level and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) enzymes were measured together with hemoglobin (Hgb), hematocrit (Hct), iron, ferritin and the mean erythrocyte volume (MCV) levels. The most frequent meat consumption was on every other day in controls, but once a week in the first and last trimester groups. In addition, the most frequent egg consumption was on every other day and once a week in contro ls, but rare in the first trimester group, and once a week in the last trimester group. Although iron and vitamin use was 10% and 30% in the first trimester group, it was 50% and 65% respectively in the last trimester group. The MDA level was higher, and t he SOD, CAT and GSH-Px enzyme activities were lower in both pregnant groups than controls. The Hgb and Hct values were lower in the last trimester group compared to the controls and the first trimester group. The first trimester group and the controls were similar in terms of Hgb and Hct levels. There was no significant difference among groups in terms of ferritin, iron or MCV values. It was concluded that; a) the egg and meat consumption might decrease with the progress of pregnancy, b) the oxidative stress increased in pregnancy, c) Hgb and Hct values might be lower in the last trimester group despite increased intake of oral iron and vitamin supplements, and normal serum iron levels due to decreased CAT activity. Therefore, more studies are needed to demonstrate the relationship among oxidative stress, anemia and CAT enzyme activity in pregnancy. © 2022, Yuzuncu Yil Universitesi Tip Fakultesi. All rights reserved.
Oxidative Stress and Antioxidant Enzyme Activities in Newborns With Oesophageal Atresia and Their Mothers
(Sage Publications Ltd, 2012) Melek, M.; Demir, H.; Bilici, S.; Beger, B.; Cobanoglu, U.; Meral, I.; Ozmen, E.
OBJECTIVE: To measure the oxidant/antioxidant status of newborn babies with oesophageal atresia and their mothers, compared with healthy control subjects. METHODS: This case control study included 40 participants: 10 newborns with oesophageal atresia and their mothers, and 10 healthy newborns and their mothers. Whole blood malondialdehyde (MDA) levels and the activities of antioxidant enzymes (catalase, carbonic anhydrase [CA], glucose-6-phosphate dehydrogenase [G-6-PD], and superoxide dismutase [SOD]) were measured. RESULTS: MDA levels and CA activity were significantly higher, and catalase, SOD and G-6-PD activities were significantly lower, in newborns with oesophageal atresia and their mothers than in healthy newborns and their mothers. Although CA activity was similar between the newborns and mothers in the patient group, it was significantly lower in newborns than in mothers in the healthy group. CONCLUSIONS: Increased lipid peroxidation might play an important role in the pathogenesis of oesophageal atresia. Impairment of the free radical/antioxidant balance may lead to increased free radical and decreased antioxidant levels in oesophageal atresia.
Short-Term Levosimendan Treatment Protects Rat Testes Against Oxidative Stress
(Assoc Bras Divulg Cientifica, 2012) Yuksel, M. B.; Kavak, S.; Gecit, I.; Basel, H.; Gumrukcuoglu, H. A.; Demir, H.; Meral, I.
The objective of this study was to evaluate the effect of short-term levosimendan exposure on oxidant/antioxidant status and trace element levels in the testes of rats under physiological conditions. Twenty male Wistar albino rats were randomly divided into two groups of 10 animals each. Group 1 was not exposed to levosimendan and served as control. Levosimendan (12 mu g/kg) diluted in 10 mL 0.9% NaCl was administered intraperitoneally to group 2. Animals of both groups were sacrificed after 3 days and their testes were harvested for the determination of changes in tissue oxidant/antioxidant status and trace element levels. Tissue malondialdehyde (MDA) was significantly lower in the levosimendan group (P < 0.001) than in the untreated control group and superoxide dismutase and glutathione peroxidase (GSH-Px) levels were significantly higher in the levosimendan group (P < 0.001). Carbonic anhydrase, catalase and GSH levels were not significantly different from controls. Mg and Zn levels of testes were significantly higher (P < 0.001) and Co, Pb, Cd, Mn, and Cu were significantly lower (P < 0.001) in group 2 compared to group 1. Fe levels were similar for the two groups (P = 0.94). These results suggest that 3-day exposure to levosimendan induced a significant decrease in tissue MDA level, which is a lipid peroxidation product and an indicator of oxidative stress, and a significant increase in the activity of an important number of the enzymes that protect against oxidative stress in rat testes.