Kenan Gumustekin

Abant İzzet Baysal Üniversitesi, Claudiopolis, Bolu, Turkey

Are you Kenan Gumustekin?

Claim your profile

Publications (25)36.6 Total impact

  • S Taysi · M S Keles · K Gumustekin · M Akyuz · A Boyuk · O Cikman · N Bakan
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to evaluate plasma homocysteine (Hcy), malondialdehyde (MDA), glutathione (GSH) levels, glutathione peroxidase (GSH-Px) and glutathione-S-transferase (GST) activities and liver tissue S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) levels in control and vitamin B6-deficient rats. Thirty-two male rats with a weight of 65-75 g were used for the experiment. The rats were divided into control (n=16) and vitamin B6-deficient groups. At the end of the experiment, the animals were anesthetized with ketamine-HCl (Ketalar, 20 mg/kg, i.p.), and the blood was collected by cardiac puncture after thoracotomy. Plasma Hcy, pyridoxal phosphate (PLP), liver SAM, SAH levels measured by an isocratic system with high performance liquid chromatography. Plasma GSH-Px, GSH activities and GSH, MDA levels were carried out using a spectrophotometer. Plasma Hcy, MDA, liver tissue SAH levels were significantly increased, whereas plasma GSH, PLP, liver tissue SAM levels, plasma GST, GSH-Px activities and SAM/SAH ratio were decreased compared to those of control group. Vitamin B6 deficiency causes an increase in plasma homocysteine levels. Thus, we think that vitamin B6 supplementation could be used for therapeutic purposes in hyperhomocysteinemia condition.
    No preview · Article · Jan 2015
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to determine the effects of diabetes mellitus, ovarian aging, ovarian aging plus diabetes mellitus, and the oxidative stress generated by these conditions on the lungs of rats, using histopatological and biochemical parameters. In the diabetic group, some abnormalities like bronchial hyperplasia, edema, haemorrhage, pulmonary capillary dilatation, breakdown of alveoli, mononuclear inflammatory cells, and moderate immunoreactivity were observed. Although, the results obtained from the ovariectomy group were similar to those of the diabetic group, haemorrhagic area and an increase in apoptotic cell density were observed more in this group compared to the diabetic group. In the last group, both immunoreactivity rate and the degree of abnormal structure were more remarkable compared to the other groups. Our biochemical results confirmed the histological findings. Conclusively, increase in the reactive oxygen species (ROS) levels of the cell, regardless of whatever reason, may lead to many other functional failures as well produce some disease conditions. Our results suggested that oxidative load increased in rats with ovariectomy-induced menopause with or without diabetes; however, enzymatic free radical defense mechanisms were damaged in the diabetic rats. The results also suggested that the antioxidant ability of the female sex hormone acts as a protective factor against diabetes.
    Full-text · Article · Jul 2012 · African journal of pharmacy and pharmacology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The effects of vitamin E and Hippophea rhamnoides L. extract (HRe-1) on nicotine-induced oxidative stress in rat heart were investigated. There were eight rats per group and supplementation period was 3 weeks. The groups were: nicotine [0.5 mg kg(-1)day(-1), intraperitoneal (i.p.)]; nicotine plus vitamin E [75 mg kg(-1)day(-1), intragastric (i.g.)]; nicotine plus HRe-1 (250 mg kg(-1)day(-1), i.g.); and the control group (receiving only vehicles). Nicotine increased the malondialdehyde level, which was prevented by both vitamin E and HRe-1. Glutathione peroxidase (GPx) activity in nicotine plus vitamin E supplemented group was higher than the others. Glutathione S-transferase (GST) activity in nicotine plus HRe-1 supplemented group was increased compared with the control group. Catalase activity was higher in nicotine group compared with others. GPx activity in nicotine plus vitamin E supplemented group was elevated compared with the others. Total and non-enzymatic superoxide scavenger activities in nicotine plus vitamin E supplemented group were lower than nicotine plus HRe-1 supplemented group. Superoxide dismutase (SOD) activity was higher in nicotine plus HRe-1 supplemented group compared with others. Glutathione reductase activity and nitric oxide level were not affected. Increased SOD and GST activities might have taken part in the prevention of nicotine-induced oxidative stress in HRe-1 supplemented group in rat heart. Flavonols such as quercetin, and isorahmnetin, tocopherols such as alpha-tocopherol and beta-tocopherol and carotenoids such as alpha-carotene and beta-carotene, reported to be present in H. rhamnoides L. extracts may be responsible for the antioxidant effects of this plant extract.
    Full-text · Article · Jun 2010 · Cell Biochemistry and Function
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to evaluate lipid peroxidation (LP) and free radical scavenging enzyme activities in kidney tissue of vitamin B(6)-deficient rats. The rats were divided into control and vitamin B(6)-deficient groups. After 4 weeks of feeding, animals in all groups were anesthetized by thiopental sodium (50 mg/kg). Thoraces were opened, 2 mL blood samples were taken from aortas, then the rats were killed by cervical dislocation, and kidney tissues were removed. Biochemical measurements in kidney tissue were carried out using a spectrophotometer. Total superoxide scavenger activity (TSSA), nonenzymatic superoxide scavenger activity (NSSA), superoxide dismutase (SOD) activities, and antioxidant potential (AOP) values in the vitamin B(6)-deficient group were significantly lower than those of the control group, whereas glutathione peroxidase (GSH-Px), glutathione reductase (GRD), glutathione-S-transferase (GST) activities, and malondialdehyde (MDA) level were significantly higher than those of the control group (p < 0.05). The results show that vitamin B(6) deficiency causes an attenuation in antioxidant defense system and an increase in oxidative stress in kidney tissue of rats.
    No preview · Article · Jun 2010 · Renal Failure
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The effects of vitamin E and Hippophae rhamnoides L. (Elaeagnaceae) extract (HRe-1) on nicotine-induced oxidative stress in rat liver were investigated. Four groups, eight rats each, were used in this study, and the supplementation period was 3 weeks. The groups were: nicotine (0.5 mg/kg/day, intraperitoneal (i.p.)); nicotine plus vitamin E (75 mg/kg/day, intragastric (i.g.)); nicotine plus HRe-1 (250 mg/kg/day, i.g.); and the control group. The malondialdehyde and nitric oxide levels, glutathione peroxidase, glutathione S-transferase, glutathione reductase, superoxide dismutase, and total and non-enzymatic superoxide scavenger activities were measured spectrophotometrically in supernatants of the tissue homogenates. Nicotine increased the malondialdehyde level in liver tissue compared with control. This nicotine-induced increase in lipid peroxidation was prevented by both vitamin E and HRe-1. Superoxide dismutase activity was higher in the nicotine plus vitamin E-supplemented group compared with nicotine and control groups. Glutathione reductase activity was higher in the nicotine group compared with the control group. However, glutathione peroxidase activity in the control group was higher than the levels in the nicotine, and the nicotine plus HRe-1 supplemented groups. The nitric oxide level was higher in the nicotine group compared with all other groups. Total and non-enzymatic superoxide scavenger activities and glutathione S-transferase activity were not affected by any of the treatments. Our results suggest that Hippophae rhamnoides extract as well as vitamin E can protect the liver against nicotine-induced oxidative stress.
    Full-text · Article · May 2010 · Pharmaceutical Biology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of the present experimental study was to determine and compare the effect of Hippophae rhamnoides L. extract (HRe-1) and of dexpanthenol on the blood flow of a wound region, in rats using xenon-133 ((133)Xe) clearance technique. METHODS: Burn wounds were made on both thighs of rats and, HRe-1 and dexpanthenol were applied topically on the wound region only in the right thigh for a period of 8 days. The effect of HRe-1 and of dexpanthenol on blood flow of the wound region was assessed before and after their topical application by using the (133)Xe clearance technique. RESULTS: HRe-1 increased significantly blood flow of the wound region (P<0.05). Dexpanthenol showed a smaller increase in blood flow. In conclusion, our results in rats suggest that HRe-1 increases blood flow of the wound area and can be used for the treatment of skin wound healing, preferably than dexpanthenol.
    Full-text · Article · Jun 2009 · Hellenic journal of nuclear medicine
  • Source
    Erhan Varoglu · Bedri Seven · Kenan Gumustekin · Omer Aktas · Ali Sahin · Senol Dane
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of the present experimental study was to determine and to compare the effects of vitamin E and of selenium on the blood flow to a wound region in rats, using the xenon-133 (133Xe) clearance technique. Burn wounds were made on the right thighs of rats followed by oral administration of vitamin E or selenium for a period of 10 days. The effect of vitamin E and of selenium individually on blood flow in the wound region was assessed before and after oral administration using the 133Xe clearance technique. Both vitamin E and selenium significantly increased the blood flow in the wound region (P<0.05). Our results in rats suggest that both vitamin E and selenium have beneficial effects on the skin wound healing process by increasing the skin blood flow. KeywordsVitamin E-Selenium-Wound healing-Blood flow-Xenon-133
    Full-text · Article · Apr 2009 · Central European Journal of Medicine
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to investigate the effects of low levels of zinc intake on the rat mandible and maxilla during growth and to compare these results with those of zinc-containing rats. The study was carried out on 14 Sprague-Dawley rats. The rats were randomly divided into two groups. Group I rats were fed with a Zn-deficient diet, and Group II rats with a Zn-containing diet. At the end of the fourth week on the experimental diet, all the rats were killed and blood samples were taken. Serum Zn levels were measured by atomic absorption spectrophotometry. Then, the skulls and mandibles were freed from soft tissues and measurements were made on the dry skulls, the mandibles, and teeth in both of the two groups. The zinc-deficient group showed a significantly lower value in dry skull, mandible, and teeth measurements when compared with those of the Group II. Changes in zinc intake might exert an effect on the growth of craniofacial structures. A low-zinc diet during adolescence might slow bone and teeth growth and enhance the risk of oral, periodontal, and orthodontic problems in later years.
    Preview · Article · Feb 2009 · European journal of dentistry
  • Source
    S Taysi · N Oztasan · H Efe · M F Polat · K Gumustekin · E Siktar · E Canakci · F Akcay · S Dane · M Gul
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to investigate whether an 8-week treadmill training attenuates exercise-induced oxidative stress in rat liver. Male rats were divided into untrained and trained groups. Endurance training consisted of treadmill running at a speed of 2.1 km/h, 1.5 h/day, 5 days a week for 8 weeks. To see the effects of endurance training on acute exhaustive exercise induced oxidative stress, untrained and trained rats were further devided into two groups: animals killed at rest and those killed after acute exhaustive exercise, in which the rats run at 2.1 km/h (10% uphill) until exhaustion. Acute exhaustive exercise increased malondialdehyde level in untrained but not in trained rats. It decreased the activity of glutathione peroxidase and total (enzymatic plus non-enzymatic) superoxide scavenger activity in untrained rats and catalase activity in trained rats. However, it did not affect glutathione S-transferase, glutathione reductase, superoxide dismutase and non-enzymatic superoxide radical scavenger activities in both trained and untrained rats. On the other hand, endurance training decreased glutathione peroxidase and glutathione S-transferase activities. The results suggested that endurance training attenuated exercise-induced oxidative stress in liver, probably by preventing the decreases in glutathione peroxidase and total superoxide scavenger activities during exercise.
    Full-text · Article · Jan 2009 · Acta Physiologica Hungarica
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to evaluate the antioxidant role of melatonin against radiation-induced cataract in the rat lens after total cranial irradiation with a single 5 Gray (Gy) dose of gamma irradiation. Twenty-eight Sprague-Dawley rats were used for the experiment.The rats were randomly divided into four equal groups. The control group did not receive melatonin or irradiation but received both 0.1 ml physiological saline intraperitoneally and sham irradiation. The irradiation (IR) group received 5 Gy gamma irradiation to the total cranium as a single dose plus 0.1 ml physiological saline intraperitoneally. The melatonin plus IR group received irradiation to the total cranium plus 5 mg/kg/day melatonin intraperitoneally. The melatonin group received only 5 mg/kg/day melatonin plus sham-irradiation. Biochemical parameters measured in murine lenses were carried out using spectrophotometric techniques. Lens antioxidant capacity, as measured by levels of total superoxide scavenger activity (TSSA), non-enzymatic superoxide scavenger activity (NSSA) and glutathione reductase (GRD) activity, significantly increased in melatonin, control and melatonin plus IR groups when compared with the IR group. Lens glutathione-S-transferase (GST) activity significantly increased in control and melatonin groups when compared with the IR group. Lens malondialdehyde (MDA) levels significantly increased in the IR group when compared with control, melatonin and melatonin plus IR groups. Lens TSSA and NSSA activities significantly decreased in control and melatonin plus IR groups when compared with the melatonin group. Lens GST activity significantly increased in the control group when compared with melatonin plus IR group. Lens GRD activity significantly increased in melatonin and melatonin plus IR groups when compared with control group. Melatonin reduces oxidative stress markers and augments anti-oxidant capacity in the rat lens.
    Full-text · Article · Nov 2008 · International Journal of Radiation Biology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to investigate whether nicotine affects 6-phosphogluconate dehydrogenase (6PGD) enzyme activity in some rat tissues, and to see the modulatory effects of vitamin E on this effect in vivo. In addition, the effects of nicotine and vitamin E on 6PGD activity were also tested in vitro. The groups were: nicotine [0.5 mg/kg/day, intraperitoneal (i.p.)]; nicotine + vitamin E [75 mg/kg/day, intragastric (i.g.)]; and control group (receiving only vehicles). There were eight rats per group and supplementation period was 3 weeks. The results of in vivo study showed that nicotine activated the muscle, lungs, and testicular 6PGD enzyme activity but had no effect on heart and liver 6PGD activity. Also, nicotine + vitamin E activated the muscle, testicle, and liver 6PGD enzyme activity, while this combination had no effect on heart, and lungs in vivo. When nicotine is administered with vitamin E the increase in 6PGD enzyme activity in muscle and testicles were lower. On the other hand the increase in 6PGD enzyme activity was eliminated by vitamin E in lungs, while 6PGD enzyme activity was increased by vitamin E, which was not affected by nicotine only. In vitro results correlated well with in vivo experimental results. Our results suggest that vitamin E may favourably increase 6PGD enzyme activity in liver in nicotine treated rats, while it has negligible effects on this enzyme activity in other tissues.
    Full-text · Article · May 2008 · Journal of Enzyme Inhibition and Medicinal Chemistry
  • F. Ozabacigil · S. Beydemir · M. Ciftci · K. Gumustekin · N. Bakan
    [Show abstract] [Hide abstract]
    ABSTRACT: The antineoplastic agents cisplatin and 5-fluorouracil, have been used frequently in the medical treatments of various cancers. Cisplatin is an important drug that is administrated in the treatment of metastatic tumours of the testis, ovaries and solid tumors. 5-Fluorouracil is used in combination therapy for the treatment of some cancers including head and neck. In this study, in vitro effects of these drugs on human erythro-cytes 6-phospogluconate dehydrogenase (6PGD) and in vivo effects on rabbit erythrocytes 6PGD activity were investigated. For this purpose, human erythrocyte 6PGD was purified with 0.46 U/mg protein specific activity, 50 % yield and approximately 742-fold using 35-65 % ammonium sulfate precipitation and 2′,5′-ADP Sepharose 4B affinity chromatography. The enzyme activity was determined by Beutler's method. To check the purity of enzyme, SDS-polyacrylamide gel electrophoresis was performed. For the drugs, in vitro inhibition studies were performed and activity % - [Drug] graphs were drawn. IC50 values were calculated as 1.49 mM for cisplatin and 62.5 mM for 5-fluorouracil from these graphs. Then, Ki values for cisplatin and 5-fluorouracil were also calculated from Lineweaver-Burk graphs as 1.35 ± 0.206,53.8 ± 10.53 mM, respectively and inhibition types of the drugs were found out to be uncompetitive manner. In addition, time-dependent in vivo studies were executed for the drugs in New Zealand-albino rabbits. Cisplatin at 1 mg/kg inhibited the enzyme activity significantly (p < 0.01) 3 and 5 h after dosing. 5-fluorouracil at 25 mg/kg inhibited the enzyme activity significantly (p < 0.01) 1, 3 and 5 h after dosing. As seen from obtained IC50 and Ki values that the purified human 6PGD has been quite inhibited by these drugs.
    No preview · Article · Apr 2008
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to evaluate the lipid peroxidation, nitric oxide (NO), and free radical scavenging enzyme activities in erythrocytes of zinc (Zn)-deficient rats and to investigate the relationship among these parameters in either group. Sixteen male rats with a weight of 40-50 g were used for the experiment. The rats were divided into control (n = 8) and Zn-deficient groups. At the end of the experiment, the animals were anesthetized with ketamine-HCl (Ketalar, 20 mg/kg(-1), i.p.), and the blood was collected by cardiac puncture after thoracotomy. Blood samples were collected in vacutainer tubes without and with K(3)-EDTA as anticoagulant. Erythrocyte catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GRD), glutathione-S-transferase (GST), superoxide dismutase (SOD) activities, total (enzymatic plus nonenzymatic) superoxide scavenger activity (TSSA), nonenzymatic superoxide scavenger activity (NSSA), antioxidant potential (AOP), and serum zinc (Zn) values in the Zn-deficient group were significantly lower than those of the control group, whereas NO and malondialdehyde (MDA) levels were significantly higher than those of the control group. The results show that Zn deficiency causes a decrease in antioxidant defense system and an increase in oxidative stress in erythrocyte of rats.
    No preview · Article · Feb 2008 · Biological Trace Element Research
  • Source
    Mustafa Erat · Mehmet Ciftci · Kenan Gumustekin · Mustafa Gul
    [Show abstract] [Hide abstract]
    ABSTRACT: Effects of nicotine, and nicotine+vitamin E on glutathione reductase (Glutathione: NADP(+) oxidoreductase, EC 1.8.1.7) activity in the muscle, heart, lungs, testicles, kidney, stomach, brain and liver tissues were investigated in vivo and also in vitro. The groups were: nicotine [0.5 mg/kg/day, intraperitoneal (i.p.)]; nicotine+vitamin E [75 mg/kg/day, intragastric (i.g.)]; and control group (receiving only vehicles). There were eight rats per group and supplementation period was 3 weeks. The results showed that nicotine (0.5 mg/kg, i.p.) inhibited glutathione reductase activity significantly in the liver, lungs, heart, stomach, kidney, and testicles by approximately 61.5%, approximately 65%, approximately 70.5%, approximately 72.5%, approximately 64% and approximately 71.5%, respectively, while it had activated glutathione reductase activity in the brain by approximately 11.8%, and had no effect on the muscle glutathione reductase activity. Vitamin E supplementation prevented this nicotine-induced decrease in glutathione reductase activity in liver, lungs, heart, stomach, and kidney. However, it did not prevent this nicotine-induced decrease in testicles. In vitro studies were also carried out to elucidate the effects of nicotine and vitamin E on glutathione reductase activity. In vitro results correlated well with in vivo experimental results in liver, lungs, heart, stomach, and testicular tissues. These results show that vitamin E administration generally restores the inactivation of glutathione reductase activity due to nicotine administration in various rat tissues in vivo, and also in vitro.
    Full-text · Article · Feb 2007 · European Journal of Pharmacology
  • Source
    N. Oztasan · H. Timur · E. Siktar · K. Gumustekin · S. Akar · S. Dane · M. Gul
    [Show abstract] [Hide abstract]
    ABSTRACT: It has been reported that gonadal fat pad correlates well with the body fat in mice. The effects of endurance training on gonadal fat pad and also on ventricle mass in rat were tested in this study. Eight week treadmill training increased the endurance time and distance run in trained rats compared with sedentary rats. Endurance training decreased the weight of the left gonadal fat pad and also proportional gonadal fat pad in rats. However, Lee index, weights of the ventricles, kidneys, and testicles were not affected. The decrease in gonadal fat pad by eight week treadmill training in rat, suggests that endurance training may affect the body composition in favor of other tissues than adipose tissue probably by increasing the consumption of fats rather than carbohydrates to provide energy. Lee index, which is an obesity index used in rodents, may not be sensitive enough to detect small alterations in body fat in rats reflected as decreased gonadal fat pad by training in our study. Ventricular function should have improved to increase endurance by 8 week treadmill training not necessarily increasing the ventricular mass in our study.
    Full-text · Article · Jan 2007 · Biology of Sport
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We investigated whether 8-week treadmill training strengthens antioxidant enzymes and decreases lipid peroxidation in rat heart. The effects of acute exhaustive exercise were also investigated. Male rats (Rattus norvegicus, Sprague-Dawley strain) were divided into trained and untrained groups. Both groups were further divided equally into two groups where the rats were studied at rest and immediately after exhaustive exercise. Endurance training consisted of treadmill running 1.5 h day(-1), 5 days week(-1) for 8 weeks. For acute exhaustive exercise, graded treadmill running was conducted. Malondialdehyde level in heart tissue was not affected by acute exhaustive exercise in untrained and trained rats. The activities of glutathione peroxidase and glutathione reductase enzymes decreased by both acute exercise and training. Glutathione S-transferase and catalase activities were not affected. Total and non-enzymatic superoxide scavenger activities were not affected either. Superoxide dismutase activity decreased by acute exercise in untrained rats; however, this decrease was not observed in trained rats. Our results suggested that rat heart has sufficient antioxidant enzyme capacity to cope with exercise-induced oxidative stress, and adaptive changes in antioxidant enzymes due to endurance training are limited.
    Full-text · Article · Mar 2006 · Comparative Biochemistry and Physiology - Part A Molecular & Integrative Physiology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Effects of nicotine, and nicotine + vitamin E on glucose 6-phosphate dehydrogenase (G-6PD) activity in rat muscle, heart, lungs, testicle, kidney, stomach, brain and liver were investigated in vivo and in vitro on partially purified homogenates. Supplementation period was 3 weeks (n = 8 rats per group): nicotine [0.5 mg/kg/day, intraperitoneal (ip)]; nicotine + vitamin E [75 mg/kg/day, intragastric (ig)]; and control group (receiving only vehicle). The results showed that nicotine (0.5 mg/kg, ip) inhibited G-6PD activity in the lungs, testicle, kidney, stomach and brain by 12.5% (p < 0.001), 48% (p < 0.001), 20.8% (p < 0.001), 13% (p < 0.001) and 23.35% (p < 0.001) respectively, and nicotine had no effects on the muscle, heart and liver G6PD activity. Also, nicotine + vitamin E inhibited G-6PD activity in the testicle, brain, and liver by 32.5% (p < 0.001), 21.5% (p < 0.001), and 16.5% (p < 0.001) respectively, and nicotine + vitamin E activated the muscle, and stomach G-6PD activity by 36% (p < 0.05), and 20% (p < 0.001) respectively. In addition, nicotine + vitamin E did not have any effects on the heart, lungs, and kidney G-6PD activity. In addition, in vitro studies were also carried out to elucidate the effects of nicotine and vitamin E on G-6PD activity, which correlated well with in vivo experimental results in lungs, testicles, kidney, stomach, brain and liver tissues. These results show that vitamin E administration generally restores the inactivation of G-6PD activity due to nicotine administration in various rat tissues in vivo, and also in vitro.
    Full-text · Article · Nov 2005 · Journal of Enzyme Inhibition and Medicinal Chemistry
  • [Show abstract] [Hide abstract]
    ABSTRACT: There are asymmetries in the sizes of transverse sinus and intraocular pressure. The purpose of this study was to investigate possible relationships between the asymmetry of transverse sinuses in TOF MR venography and intraocular pressures of right and left eyes. In this study, subjects were 63 male and 42 female medical school students, aged 18-21 years (mean+/-SD; 19.72+/-0.67 years). Subjects with neurological and ophthalmologic disease, particularly dural sinus thrombosis, myopia, trauma and glaucoma, were excluded the study. Subjects were divided into five groups according to the magnitudes of the right- and left-transverse sinuses in MR venography results. There is a functional relation between intraocular pressures of the right and left eyes and asymmetry of the transverse sinus. If the transverse sinus on one side is larger and its venous drainage is greater, the intraocular pressure of the eye on this side is lower. It can be speculated that the transverse sinus size may be associated with pathogenesis of diseases with increased intraocular pressure such as glaucoma. We aim to determine the relation between the size and drainage of transverse sinuses in TOF MR venography and intraocular pressure in patients with open-angle glaucoma in our next study.
    No preview · Article · Feb 2005 · Neuroradiology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to investigate whether endurance training reduces exercise-induced oxidative stress in erythrocytes. Male rats (n=54) were divided into trained (n=28) and untrained (n=26) groups. Both groups were further divided equally into two groups where the rats were studied at rest and immediately after exhaustive exercise. Endurance training consisted of treadmill running 1.5 h x day(-1), 5 days a week for 8 weeks, reaching the speed of 2.1 km x h(-1) at the fourth week. For acute exhaustive exercise, graded treadmill running was conducted reaching the speed of 2.1 km x h(-1) at the 95th min, 10% uphill, and was continued until exhaustion. Acute exhaustive exercise increased the erythrocyte malondialdehyde level in sedentary but not in trained rats compared with the corresponding sedentary rest and trained rest groups, respectively. While acute exhaustive exercise decreased the erythrocyte superoxide dismutase activity in sedentary rats, it increased the activity of this enzyme in trained rats. On the other hand, acute exhaustive exercise increased the erythrocyte glutathione peroxidase activity in sedentary rats; however, it did not affect this enzyme activity in trained rats. Erythrocyte glutathione peroxidase activity was higher in trained groups compared with untrained sedentary group. Neither acute exhaustive exercise nor treadmill training affected the erythrocyte total glutathione level. Treadmill training increased the endurance time in trained rats compared with sedentary rats. The results of this study suggest that endurance training may be useful to prevent acute exhaustive exercise-induced oxidative stress in erythrocytes by up-regulating some of the antioxidant enzyme activities and may have implications in exercising humans.
    Full-text · Article · Jun 2004 · Arbeitsphysiologie
  • Fatih Alper · Mecit Kantarci · Senol Dane · Kenan Gumustekin · Omer Onbas · Irmak Durur
    [Show abstract] [Hide abstract]
    ABSTRACT: Time-of-flight (TOF) magnetic resonance venography (MRV) is often used to examine the intracranial dural sinuses, particularly in the evaluation of dural sinus thrombosis. The goal of the study was to evaluate the use of TOF MRV in assessing the normal anatomy of dural sinuses and their variations as sources of potential pitfalls in the diagnosis of venous sinus thrombosis. Cerebral TOF MRV obtained in 105 persons with normal MR studies were reviewed to determine the presence, aplasia and hypoplasia of the transverse sinuses. Twenty-one (20%) aplasias of the left sinus, 41 (39%) hypoplasia of the left sinus, 33 (31%) symmetric, 6 (6%) hypoplasia of the right sinus, and 4 (4%) aplasias of the right sinus cases were determined in the asymmetry in sizes of transverse sinuses. These results suggested that transverse sinus flow gaps or aplasias can be observed in approximately 24% of normal population on MR imaging. The rate of these gaps in normal subjects must be kept in mind because it can be a source of misdiagnosis in cases of suspected dural sinus thrombosis.
    No preview · Article · Feb 2004 · Cerebrovascular Diseases